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Sample records for cells regulate cns

  1. Environmental cues from CNS, PNS, and ENS cells regulate CNS progenitor differentiation

    DEFF Research Database (Denmark)

    Brännvall, Karin; Corell, Mikael; Forsberg-Nilsson, Karin;

    2008-01-01

    Cellular origin and environmental cues regulate stem cell fate determination. Neuroepithelial stem cells form the central nervous system (CNS), whereas neural crest stem cells generate the peripheral (PNS) and enteric nervous system (ENS). CNS neural stem/progenitor cell (NSPC) fate determination...... was investigated in combination with dissociated cultures or conditioned media from CNS, PNS, or ENS. Cells or media from ENS or PNS cultures efficiently promoted NSPC differentiation into neurons, glia, and smooth muscle cells with a similar morphology as the feeder culture. Together with CNS cells or its...... conditioned medium, NSPC differentiation was partly inhibited and cells remained immature. Here, we demonstrate that secreted factors from the environment can influence CNS progenitor cells to choose a PNS-like cell fate....

  2. CNS Immunity is Developmentally Regulated

    OpenAIRE

    Davis, Deirdre Shawna

    2011-01-01

    Specialized glial cells called microglia serve as the resident immunocompetent cells of the central nervous system (CNS). Though many describe microglia as having a "resting" state in the healthy brain, their processes are highly mobile and constantly survey their microenvironment (Nimmerjahn et al. 2005). In response to trauma, inflammation or infection, microglia become activated and peripheral macrophages are recruited to the CNS. Both microglial morphology and the collection of receptors...

  3. Innate Interferons Regulate CNS Inflammation

    DEFF Research Database (Denmark)

    Dieu, Ruthe; Khorooshi, Reza M. H.; Mariboe, Anne;

    -beta or have disrupted IFNAR-signaling develop more severe disease, whereas peripheral IFN-beta treatment reduced disease severity and delayed onset. Furthermore, it was recently shown that induction of type I IFNs in the CNS of mice by a TLR3-ligand was protective against EAE. We are now investigating another...

  4. CD11c(hi) Dendritic Cells Regulate Ly-6C(hi) Monocyte Differentiation to Preserve Immune-privileged CNS in Lethal Neuroinflammation.

    Science.gov (United States)

    Kim, Jin Hyoung; Choi, Jin Young; Kim, Seong Bum; Uyangaa, Erdenebelig; Patil, Ajit Mahadev; Han, Young Woo; Park, Sang-Youel; Lee, John Hwa; Kim, Koanhoi; Eo, Seong Kug

    2015-12-02

    Although the roles of dendritic cells (DCs) in adaptive defense have been defined well, the contribution of DCs to T cell-independent innate defense and subsequent neuroimmunopathology in immune-privileged CNS upon infection with neurotropic viruses has not been completely defined. Notably, DC roles in regulating innate CD11b(+)Ly-6C(hi) monocyte functions during neuroinflammation have not yet been addressed. Using selective ablation of CD11c(hi)PDCA-1(int/lo) DCs without alteration in CD11c(int)PDCA-1(hi) plasmacytoid DC number, we found that CD11c(hi) DCs are essential to control neuroinflammation caused by infection with neurotropic Japanese encephalitis virus, through early and increased infiltration of CD11b(+)Ly-6C(hi) monocytes and higher expression of CC chemokines. More interestingly, selective CD11c(hi) DC ablation provided altered differentiation and function of infiltrated CD11b(+)Ly-6C(hi) monocytes in the CNS through Flt3-L and GM-CSF, which was closely associated with severely enhanced neuroinflammation. Furthermore, CD11b(+)Ly-6C(hi) monocytes generated in CD11c(hi) DC-ablated environment had a deleterious rather than protective role during neuroinflammation, and were more quickly recruited into inflamed CNS, depending on CCR2, thereby exacerbating neuroinflammation via enhanced supply of virus from the periphery. Therefore, our data demonstrate that CD11c(hi) DCs provide a critical and unexpected role to preserve the immune-privileged CNS in lethal neuroinflammation via regulating the differentiation, function, and trafficking of CD11b(+)Ly-6C(hi) monocytes.

  5. Immune Cells Exploit a Neural Circuit to Enter the CNS

    OpenAIRE

    Kevin J Tracey

    2012-01-01

    Multiple sclerosis (MS) is associated with the appearance of autoreactive T cells in the central nervous system. Using a mouse model of MS, Arima et al. now show that this attack begins at a specific spinal cord location. T cell entry into the CNS is regulated by a reflex neural circuit originating from leg muscle contractions.

  6. Immune regulation and CNS autoimmune disease

    DEFF Research Database (Denmark)

    Antel, J P; Owens, T

    1999-01-01

    The central nervous system is a demonstrated target of both clinical and experimental immune mediated disorders. Immune regulatory mechanisms operative at the levels of the systemic immune system, the blood brain barrier, and within the CNS parenchyma are important determinants of the intensity a...

  7. Receptor Tyrosine Kinases: Molecular Switches Regulating CNS Axon Regeneration

    Directory of Open Access Journals (Sweden)

    Vasanthy Vigneswara

    2012-01-01

    Full Text Available The poor or lack of injured adult central nervous system (CNS axon regeneration results in devastating consequences and poor functional recovery. The interplay between the intrinsic and extrinsic factors contributes to robust inhibition of axon regeneration of injured CNS neurons. The insufficient or lack of trophic support for injured neurons is considered as one of the major obstacles contributing to their failure to survive and regrow their axons after injury. In the CNS, many of the signalling pathways associated with neuronal survival and axon regeneration are regulated by several classes of receptor tyrosine kinases (RTK that respond to a variety of ligands. This paper highlights and summarises the most relevant recent findings pertinent to different classes of the RTK family of molecules, with a particular focus on elucidating their role in CNS axon regeneration.

  8. Immune Privilege as an Intrinsic CNS Property: Astrocytes Protect the CNS against T-Cell-Mediated Neuroinflammation

    Directory of Open Access Journals (Sweden)

    Ulrike Gimsa

    2013-01-01

    Full Text Available Astrocytes have many functions in the central nervous system (CNS. They support differentiation and homeostasis of neurons and influence synaptic activity. They are responsible for formation of the blood-brain barrier (BBB and make up the glia limitans. Here, we review their contribution to neuroimmune interactions and in particular to those induced by the invasion of activated T cells. We discuss the mechanisms by which astrocytes regulate pro- and anti-inflammatory aspects of T-cell responses within the CNS. Depending on the microenvironment, they may become potent antigen-presenting cells for T cells and they may contribute to inflammatory processes. They are also able to abrogate or reprogram T-cell responses by inducing apoptosis or secreting inhibitory mediators. We consider apparently contradictory functions of astrocytes in health and disease, particularly in their interaction with lymphocytes, which may either aggravate or suppress neuroinflammation.

  9. Suppressors of cytokine signaling 1 and 3 are up-regulated in brain resident cells in response to virus induced inflammation of the CNS via at least two distinctive pathways

    DEFF Research Database (Denmark)

    Steffensen, Maria Abildgaard; Fenger, Christina; Christensen, Jeanette Erbo;

    2014-01-01

    Suppressors of cytokine signaling (SOCS) proteins are intracellular proteins that inhibit cytokine signaling in a variety of cell types. A number of viral infections have been associated with SOCS up-regulation; however, not much is known about the mechanisms regulating SOCS expression during viral......-cytolytic and a cytolytic virus induce marked up-regulation of SOCS1 and-3 expression. Notably, the kinetics of the observed up-regulation follows that of activity within pro-inflammatory signalling pathways and, interestingly, type II IFN, which is also a key inducer of inflammatory mediators, seems to be essential...... underlie a virus induced up-regulation of SOCS in the CNS. We found that i.c. infection with either lymphocytic choriomeningitis virus (LCMV) or yellow fever virus (YF) results in gradual up-regulation of SOCS1/3 mRNA expression peaking at day 7 post infection (p.i.). In the LCMV model, SOCS m...

  10. Kif13b Regulates PNS and CNS Myelination through the Dlg1 Scaffold.

    Directory of Open Access Journals (Sweden)

    Roberta Noseda

    2016-04-01

    Full Text Available Microtubule-based kinesin motors have many cellular functions, including the transport of a variety of cargos. However, unconventional roles have recently emerged, and kinesins have also been reported to act as scaffolding proteins and signaling molecules. In this work, we further extend the notion of unconventional functions for kinesin motor proteins, and we propose that Kif13b kinesin acts as a signaling molecule regulating peripheral nervous system (PNS and central nervous system (CNS myelination. In this process, positive and negative signals must be tightly coordinated in time and space to orchestrate myelin biogenesis. Here, we report that in Schwann cells Kif13b positively regulates myelination by promoting p38γ mitogen-activated protein kinase (MAPK-mediated phosphorylation and ubiquitination of Discs large 1 (Dlg1, a known brake on myelination, which downregulates the phosphatidylinositol 3-kinase (PI3K/v-AKT murine thymoma viral oncogene homolog (AKT pathway. Interestingly, Kif13b also negatively regulates Dlg1 stability in oligodendrocytes, in which Dlg1, in contrast to Schwann cells, enhances AKT activation and promotes myelination. Thus, our data indicate that Kif13b is a negative regulator of CNS myelination. In summary, we propose a novel function for the Kif13b kinesin in glial cells as a key component of the PI3K/AKT signaling pathway, which controls myelination in both PNS and CNS.

  11. Foxp3+ regulatory T cells control persistence of viral CNS infection.

    Directory of Open Access Journals (Sweden)

    Dajana Reuter

    Full Text Available We earlier established a model of a persistent viral CNS infection using two week old immunologically normal (genetically unmodified mice and recombinant measles virus (MV. Using this model infection we investigated the role of regulatory T cells (Tregs as regulators of the immune response in the brain, and assessed whether the persistent CNS infection can be modulated by manipulation of Tregs in the periphery. CD4(+ CD25(+ Foxp3(+ Tregs were expanded or depleted during the persistent phase of the CNS infection, and the consequences for the virus-specific immune response and the extent of persistent infection were analyzed. Virus-specific CD8(+ T cells predominantly recognising the H-2D(b-presented viral hemagglutinin epitope MV-H(22-30 (RIVINREHL were quantified in the brain by pentamer staining. Expansion of Tregs after intraperitoneal (i.p. application of the superagonistic anti-CD28 antibody D665 inducing transient immunosuppression caused increased virus replication and spread in the CNS. In contrast, depletion of Tregs using diphtheria toxin (DT in DEREG (depletion of regulatory T cells-mice induced an increase of virus-specific CD8(+ effector T cells in the brain and caused a reduction of the persistent infection. These data indicate that manipulation of Tregs in the periphery can be utilized to regulate virus persistence in the CNS.

  12. EMA: a developmentally regulated cell-surface glycoprotein of CNS neurons that is concentrated at the leading edge of growth cones.

    Science.gov (United States)

    Baumrind, N L; Parkinson, D; Wayne, D B; Heuser, J E; Pearlman, A L

    1992-08-01

    To identify cell-surface molecules that mediate interactions between neurons and their environment during neural development, we used monoclonal antibody techniques to define a developmentally regulated antigen in the central nervous system of the mouse. The antibody we produced (2A1) immunolabels cells throughout the central nervous system; we analyzed its distribution in the developing cerebral cortex, where it is expressed on cells very soon after they complete mitosis and leave the periventricular proliferative zone. Expression continues into adult life. The antibody also labels the epithelium of the choroid plexus and the renal proximal tubules, but does not label neurons of the peripheral nervous system in the dorsal root ganglia. In dissociated cell culture of embryonic cerebral cortex, 2A1 labels the surface of neurons but not glia. Immunolabeling of neurons in tissue culture is particularly prominent on the edge of growth cones, including filopodia and the leading edge of lamellipodia, when observed with either immunofluorescence or freeze-etch immunoelectron microscopy. Immunopurification with 2A1 of a CHAPS-extracted membrane preparation from brains of neonatal mice produces a broad (32-36 kD) electrophoretic band and a less prominent 70 kD band that are sensitive to N-glycosidase but not endoglycosidase H. Thus the 2A1 antibody recognizes a developmentally regulated, neuronal cell surface glycoprotein (or glycoproteins) with complex N-linked oligosaccharide side chains. We have termed the glycoprotein antigen EMA because of its prominence on the edge membrane of growth cones. EMA is similar to the M6 antigen (Lagenaur et al: J. Neurobiol. 23:71-88, 1992) in apparent molecular weight, distribution in tissue sections, and immunoreactivity on Western blots, suggesting that the two antigens are similar or identical. Expression of EMA is a very early manifestation of neuronal differentiation; its distribution on growth cones suggests a role in mediating the

  13. Immortalized neural progenitor cells for CNS gene transfer and repair.

    Science.gov (United States)

    Martínez-Serrano, A; Björklund, A

    1997-11-01

    Immortalized multipotent neural stem and progenitor cells have emerged as a highly convenient source of tissue for genetic manipulation and ex vivo gene transfer to the CNS. Recent studies show that these cells, which can be maintained and genetically transduced as cell lines in culture, can survive, integrate and differentiate into both neurons and glia after transplantation to the intact or damaged brain. Progenitors engineered to secrete trophic factors, or to produce neurotransmitter-related or metabolic enzymes can be made to repopulate diseased or injured brain areas, thus providing a new potential therapeutic tool for the blockade of neurodegenerative processes and reversal of behavioural deficits in animal models of neurodegenerative diseases. With further technical improvements, the use of immortalized neural progenitors may bring us closer to the challenging goal of targeted and effective CNS repair.

  14. The cell biology of CNS myelination.

    Science.gov (United States)

    Hughes, Ethan G; Appel, Bruce

    2016-08-01

    Myelination of axons in the central nervous system results from the remarkable ability of oligodendrocytes to wrap multiple axons with highly specialized membrane. Because myelin membrane grows as it ensheaths axons, cytoskeletal rearrangements that enable ensheathment must be coordinated with myelin production. Because the myelin sheaths of a single oligodendrocyte can differ in thickness and length, mechanisms that coordinate axon ensheathment with myelin growth likely operate within individual oligodendrocyte processes. Recent studies have revealed new information about how assembly and disassembly of actin filaments helps drive the leading edge of nascent myelin membrane around and along axons. Concurrently, other investigations have begun to uncover evidence of communication between axons and oligodendrocytes that can regulate myelin formation.

  15. Endovascular transplantation of stem cells to the injured rat CNS

    Energy Technology Data Exchange (ETDEWEB)

    Lundberg, Johan; Soederman, Mikael; Andersson, Tommy; Holmin, Staffan [Karolinska University Hospital, Department of Clinical Neuroscience, Karolinska Institutet, Department of Neuroradiology, Stockholm (Sweden); Le Blanc, Katarina [Karolinska University Hospital, Department of Stem Cell Research, Karolinska Institutet, Department of Clinical Immunology, Stockholm (Sweden)

    2009-10-15

    Transplantation procedures using intraparenchymal injection of stem cells result in tissue injury in addition to associated surgical risks. Intravenous injection of mesenchymal stem cells gives engraftment to lesions, but the method has low efficiency and specificity. In traumatic brain injuries (TBI), there is a transient breakdown of the blood-brain barrier and an inflammatory response, which increase migration of cells from blood to parenchyma. The aim of this investigation was to analyze the effect of intra-arterial administration on cellular engraftment. Experimental TBI was produced in a rat model. Endovascular technique was used to administer human mesenchymal stem cells in the ipsilateral internal carotid artery. Evaluation of engraftment and side effects were performed by immunohistochemical analysis of the brain and several other organs. The results were compared to intravenous administration of stem cells. Intra-arterial transplantion of mesenchymal stem cells resulted in central nervous system (CNS) engraftment without thromboembolic ischemia. We observed a significantly higher number of transplanted cells in the injured hemisphere after intra-arterial compared to intravenous administration both 1 day (p<0.01) and 5 days (p<0.05) after the transplantation. Some cells were also detected in the spleen but not in the other organs analyzed. Selective intra-arterial administration of mesenchymal stem cells to the injured CNS is a minimally invasive method for transplantation. The method is significantly more efficient than the intravenous route and causes no side effects in the current model. The technique can potentially be used for repeated transplantation to the CNS after TBI and in other diseases. (orig.)

  16. Programmed cell death in developing human fetal CNS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The spatial and temporal distributions of programmed cell death (PCD) in developing central nervous system (CNS) of human fetuses ranging from 12 to 39 weeks of gestation were investigated using techniques of flow cytometry and terminal transferase-mediated nick end labeling (TUNEL). The results showed that PCD did occur in every representative brain region of all fetuses examined in different stages. It was found that there were two peaks of PCD appearing at the 12th and 39th weeks respectively, which suggested that the first peak of apoptosis may be involved in the selective elimination of neurons overproduced during the early development and the second may play an important role in establishing the correct neuronal circuitry.

  17. Schwann cells but not olfactory ensheathing cells inhibit CNS myelination via the secretion of connective tissue growth factor.

    Science.gov (United States)

    Lamond, Rebecca; Barnett, Susan C

    2013-11-20

    Cell transplantation is a promising strategy to promote CNS repair and has been studied for several decades with a focus on glial cells. Promising candidates include Schwann cells (SCs) and olfactory ensheathing cells (OECs). Both cell types are thought to be neural crest derived and share many properties in common, although OECs appear to be a better candidate for transplantation by evoking less astrogliosis. Using CNS mixed myelinating rat cultures plated on to a monolayer of astrocytes, we demonstrated that SCs, but not OECs, secrete a heat labile factor(s) that inhibits oligodendrocyte myelination. Comparative qRT-PCR and ELISA showed that SCs expressed higher levels of mRNA and protein for connective tissue growth factor (CTGF) than OECs. Anti-CTGF reversed the SCM-mediated effects on myelination. Both SCM and CTGF inhibited the differentiation of purified rat oligodendrocyte precursor cells (OPCs). Furthermore, pretreatment of astrocyte monolayers with SCM inhibited CNS myelination and led to transcriptional changes in the astrocyte, corresponding to upregulation of bone morphogenic protein 4 mRNA and CTGF mRNA (inhibitors of OPC differentiation) and the downregulation of insulin-like growth factor 2 mRNA (promoter of OPC differentiation). CTGF pretreatment of astrocytes increased their expression of CTGF, suggesting that this inhibitory factor can be positively regulated in astrocytes. These data provide evidence for the advantages of using OECs, and not mature SCs, for transplant-mediated repair and provide more evidence that they are a distinct and unique glial cell type.

  18. The Impact of Neural Stem Cell Biology on CNS Carcinogenesis and Tumor Types

    Directory of Open Access Journals (Sweden)

    K. M. Kurian

    2011-01-01

    Full Text Available The incidence of gliomas is on the increase, according to epidemiological data. This increase is a conundrum because the brain is in a privileged protected site behind the blood-brain barrier, and therefore partially buffered from environmental factors. In addition the brain also has a very low proliferative potential compared with other parts of the body. Recent advances in neural stem cell biology have impacted on our understanding of CNS carcinogenesis and tumor types. This article considers the cancer stem cell theory with regard to CNS cancers, whether CNS tumors arise from human neural stem cells and whether glioma stem cells can be reprogrammed.

  19. Locus Ceruleus Norepinephrine Release: A Central Regulator of CNS Spatio-Temporal Activation?

    Science.gov (United States)

    Atzori, Marco; Cuevas-Olguin, Roberto; Esquivel-Rendon, Eric; Garcia-Oscos, Francisco; Salgado-Delgado, Roberto C; Saderi, Nadia; Miranda-Morales, Marcela; Treviño, Mario; Pineda, Juan C; Salgado, Humberto

    2016-01-01

    Norepinephrine (NE) is synthesized in the Locus Coeruleus (LC) of the brainstem, from where it is released by axonal varicosities throughout the brain via volume transmission. A wealth of data from clinics and from animal models indicates that this catecholamine coordinates the activity of the central nervous system (CNS) and of the whole organism by modulating cell function in a vast number of brain areas in a coordinated manner. The ubiquity of NE receptors, the daunting number of cerebral areas regulated by the catecholamine, as well as the variety of cellular effects and of their timescales have contributed so far to defeat the attempts to integrate central adrenergic function into a unitary and coherent framework. Since three main families of NE receptors are represented-in order of decreasing affinity for the catecholamine-by: α2 adrenoceptors (α2Rs, high affinity), α1 adrenoceptors (α1Rs, intermediate affinity), and β adrenoceptors (βRs, low affinity), on a pharmacological basis, and on the ground of recent studies on cellular and systemic central noradrenergic effects, we propose that an increase in LC tonic activity promotes the emergence of four global states covering the whole spectrum of brain activation: (1) sleep: virtual absence of NE, (2) quiet wake: activation of α2Rs, (3) active wake/physiological stress: activation of α2- and α1-Rs, (4) distress: activation of α2-, α1-, and β-Rs. We postulate that excess intensity and/or duration of states (3) and (4) may lead to maladaptive plasticity, causing-in turn-a variety of neuropsychiatric illnesses including depression, schizophrenic psychoses, anxiety disorders, and attention deficit. The interplay between tonic and phasic LC activity identified in the LC in relationship with behavioral response is of critical importance in defining the short- and long-term biological mechanisms associated with the basic states postulated for the CNS. While the model has the potential to explain a large

  20. Locus Ceruleus Norepinephrine Release: A Central Regulator of CNS Spatio-Temporal Activation?

    Science.gov (United States)

    Atzori, Marco; Cuevas-Olguin, Roberto; Esquivel-Rendon, Eric; Garcia-Oscos, Francisco; Salgado-Delgado, Roberto C.; Saderi, Nadia; Miranda-Morales, Marcela; Treviño, Mario; Pineda, Juan C.; Salgado, Humberto

    2016-01-01

    Norepinephrine (NE) is synthesized in the Locus Coeruleus (LC) of the brainstem, from where it is released by axonal varicosities throughout the brain via volume transmission. A wealth of data from clinics and from animal models indicates that this catecholamine coordinates the activity of the central nervous system (CNS) and of the whole organism by modulating cell function in a vast number of brain areas in a coordinated manner. The ubiquity of NE receptors, the daunting number of cerebral areas regulated by the catecholamine, as well as the variety of cellular effects and of their timescales have contributed so far to defeat the attempts to integrate central adrenergic function into a unitary and coherent framework. Since three main families of NE receptors are represented—in order of decreasing affinity for the catecholamine—by: α2 adrenoceptors (α2Rs, high affinity), α1 adrenoceptors (α1Rs, intermediate affinity), and β adrenoceptors (βRs, low affinity), on a pharmacological basis, and on the ground of recent studies on cellular and systemic central noradrenergic effects, we propose that an increase in LC tonic activity promotes the emergence of four global states covering the whole spectrum of brain activation: (1) sleep: virtual absence of NE, (2) quiet wake: activation of α2Rs, (3) active wake/physiological stress: activation of α2- and α1-Rs, (4) distress: activation of α2-, α1-, and β-Rs. We postulate that excess intensity and/or duration of states (3) and (4) may lead to maladaptive plasticity, causing—in turn—a variety of neuropsychiatric illnesses including depression, schizophrenic psychoses, anxiety disorders, and attention deficit. The interplay between tonic and phasic LC activity identified in the LC in relationship with behavioral response is of critical importance in defining the short- and long-term biological mechanisms associated with the basic states postulated for the CNS. While the model has the potential to explain a

  1. In Vivo Reprogramming for CNS Repair: Regenerating Neurons from Endogenous Glial Cells.

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    Li, Hedong; Chen, Gong

    2016-08-17

    Neuroregeneration in the CNS has proven to be difficult despite decades of research. The old dogma that CNS neurons cannot be regenerated in the adult mammalian brain has been overturned; however, endogenous adult neurogenesis appears to be insufficient for brain repair. Stem cell therapy once held promise for generating large quantities of neurons in the CNS, but immunorejection and long-term functional integration remain major hurdles. In this Perspective, we discuss the use of in vivo reprogramming as an emerging technology to regenerate functional neurons from endogenous glial cells inside the brain and spinal cord. Besides the CNS, in vivo reprogramming has been demonstrated successfully in the pancreas, heart, and liver and may be adopted in other organs. Although challenges remain for translating this technology into clinical therapies, we anticipate that in vivo reprogramming may revolutionize regenerative medicine by using a patient's own internal cells for tissue repair. PMID:27537482

  2. CNS expression of B7-H1 regulates pro-inflammatory cytokine production and alters severity of Theiler's virus-induced demyelinating disease.

    Directory of Open Access Journals (Sweden)

    D'Anne S Duncan

    Full Text Available The CNS is a unique organ due to its limited capacity for immune surveillance. As macrophages of the CNS, microglia represent a population originally known for the ability to assist neuronal stability, are now appreciated for their role in initiating and regulating immune responses in the brain. Theiler's murine encephalomyelitis virus (TMEV-induced demyelinating disease is a mouse model of multiple sclerosis (MS. In response to TMEV infection in vitro, microglia produce high levels of inflammatory cytokines and chemokines, and are efficient antigen-presenting cells (APCs for activating CD4(+ T cells. However, the regulatory function of microglia and other CNS-infiltrating APCs in response to TMEV in vivo remains unclear. Here we demonstrate that microglia increase expression of proliferating cell nuclear antigen (PCNA, and phenotypically express high levels of major histocompatibility complex (MHC-Class I and II in response to acute infection with TMEV in SJL/J mice. Microglia increase expression of the inhibitory co-stimulatory molecule, B7-H1 as early as day 5 post-infection, while CNS-infiltrating CD11b(+CD11c(-CD45(HIGH monocytes/macrophages and CD11b(+CD11c(+CD45(HIGH dendritic cells upregulate expression of B7-H1 by day 3 post-infection. Utilizing a neutralizing antibody, we demonstrate that B7-H1 negatively regulates TMEV-specific ex vivo production of interferon (IFN-γ, interleukin (IL-17, IL-10, and IL-2 from CD4(+ and CD8(+ T cells. In vivo blockade of B7-H1 in SJL/J mice significantly exacerbates clinical disease symptoms during the chronic autoimmune stage of TMEV-IDD, but only has minimal effects on viral clearance. Collectively, these results suggest that CNS expression of B7-H1 regulates activation of TMEV-specific T cells, which affects protection against TMEV-IDD.

  3. Immunopharmacological intervention for successful neural stem cell therapy: New perspectives in CNS neurogenesis and repair.

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    Dooley, Dearbhaile; Vidal, Pia; Hendrix, Sven

    2014-01-01

    The pharmacological support and stimulation of endogenous and transplanted neural stem cells (NSCs) is a major challenge in brain repair. Trauma to the central nervous system (CNS) results in a distinct inflammatory response caused by local and infiltrating immune cells. This makes NSC-supported regeneration difficult due to the presence of inhibitory immune factors which are upregulated around the lesion site. The continual and dual role of the neuroinflammatory response leaves it difficult to decipher upon a single modulatory strategy. Therefore, understanding the influence of cytokines upon regulation of NSC self-renewal, proliferation and differentiation is crucial when designing therapies for CNS repair. There is a plethora of partially conflicting data in vitro and in vivo on the role of cytokines in modulating the stem cell niche and the milieu around NSC transplants. This is mainly due to the pleiotropic role of many factors. In order for cell-based therapy to thrive, treatment must be phase-specific to the injury and also be personalized for each patient, i.e. taking age, sex, neuroimmune and endocrine status as well as other key parameters into consideration. In this review, we will summarize the most relevant information concerning interleukin (IL)-1, IL-4, IL-10, IL-15, IFN-γ, the neuropoietic cytokine family and TNF-α in order to extract promising therapeutic approaches for further research. We will focus on the consequences of neuroinflammation on endogenous brain stem cells and the transplantation environment, the effects of the above cytokines on NSCs, as well as immunopharmacological manipulation of the microenvironment for potential therapeutic use.

  4. Arginase-1 is expressed exclusively by infiltrating myeloid cells in CNS injury and disease.

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    Greenhalgh, Andrew D; Passos Dos Santos, Rosmarini; Zarruk, Juan Guillermo; Salmon, Christopher K; Kroner, Antje; David, Samuel

    2016-08-01

    Resident microglia and infiltrating myeloid cells play important roles in the onset, propagation, and resolution of inflammation in central nervous system (CNS) injury and disease. Identifying cell type-specific mechanisms will help to appropriately target interventions for tissue repair. Arginase-1 (Arg-1) is a well characterised modulator of tissue repair and its expression correlates with recovery after CNS injury. Here we assessed the cellular localisation of Arg-1 in two models of CNS damage. Using microglia specific antibodies, P2ry12 and Fc receptor-like S (FCRLS), we show the LysM-EGFP reporter mouse is an excellent model to distinguish infiltrating myeloid cells from resident microglia. We show that Arg-1 is expressed exclusively in infiltrating myeloid cells but not microglia in models of spinal cord injury (SCI) and experimental autoimmune encephalomyelitis (EAE). Our in vitro studies suggest that factors in the CNS environment prevent expression of Arg-1 in microglia in vivo. This work suggests different functional roles for these cells in CNS injury and repair and shows that such repair pathways can be switched on in infiltrating myeloid cells in pro-inflammatory environments. PMID:27126514

  5. Primary CNS T-cell Lymphomas: A Clinical, Morphologic, Immunophenotypic, and Molecular Analysis.

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    Menon, Madhu P; Nicolae, Alina; Meeker, Hillary; Raffeld, Mark; Xi, Liqiang; Jegalian, Armin G; Miller, Douglas C; Pittaluga, Stefania; Jaffe, Elaine S

    2015-12-01

    Primary central nervous system (CNS) lymphomas are relatively rare with the most common subtype being diffuse large B-cell lymphoma. Primary CNS T-cell lymphomas (PCNSTL) account for 1 mutation, and none showed overlapping mutations. These included mutations in DNMT3A, KRAS, JAK3, STAT3, STAT5B, GNB1, and TET2 genes, genes implicated previously in other T-cell neoplasms. The outcome was heterogenous; 2 patients are alive without disease, 4 are alive with disease, and 6 died of disease. In conclusion, PCNSTLs are histologically and genomically heterogenous with frequent phenotypic aberrancy and a cytotoxic phenotype in most cases. PMID:26379152

  6. Non-neuronal Cells in ALS: Role of Glial, Immune cells and Blood-CNS Barriers.

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    Puentes, Fabiola; Malaspina, Andrea; van Noort, Johannes M; Amor, Sandra

    2016-03-01

    Neurological dysfunction and motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is strongly associated with neuroinflammation reflected by activated microglia and astrocytes in the CNS. In ALS endogenous triggers in the CNS such as aggregated protein and misfolded proteins activate a pathogenic response by innate immune cells. However, there is also strong evidence for a neuroprotective immune response in ALS. Emerging evidence also reveals changes in the peripheral adaptive immune responses as well as alterations in the blood brain barrier that may aid traffic of lymphocytes and antibodies into the CNS. Understanding the triggers of neuroinflammation is key to controlling neuronal loss. Here, we review the current knowledge regarding the roles of non-neuronal cells as well as the innate and adaptive immune responses in ALS. Existing ALS animal models, in particular genetic rodent models, are very useful to study the underlying pathogenic mechanisms of motor neuron degeneration. We also discuss the approaches used to target the pathogenic immune responses and boost the neuroprotective immune pathways as novel immunotherapies for ALS. PMID:26780491

  7. CNS Infiltration of Peripheral Immune Cells: D-Day for Neurodegenerative Disease?

    OpenAIRE

    Rezai-Zadeh, Kavon; Gate, David; Town, Terrence

    2009-01-01

    While the central nervous system (CNS) was once thought to be excluded from surveillance by immune cells, a concept known as “immune privilege,” it is now clear that immune responses do occur in the CNS—giving rise to the field of neuroimmunology. These CNS immune responses can be driven by endogenous (glial) and/or exogenous (peripheral leukocyte) sources and can serve either productive or pathological roles. Recent evidence from mouse models supports the notion that infiltration of peripher...

  8. Infected splenic dendritic cells are sufficient for prion transmission to the CNS in mouse scrapie

    OpenAIRE

    Aucouturier, Pierre; Geissmann, Frédéric; Damotte, Diane; Saborio, Gabriela P.; Meeker, Harry C.; Kascsak, Regina; Kascsak, Richard; Carp, Richard I.; Wisniewski, Thomas

    2001-01-01

    Transmissible spongiform encephalopathies display long incubation periods at the beginning of which the titer of infectious agents (prions) increases in peripheral lymphoid organs. This “replication” leads to a progressive invasion of the CNS. Follicular dendritic cells appear to support prion replication in lymphoid follicles. However, the subsequent steps of neuroinvasion remain obscure. CD11c+ dendritic cells, an unrelated cell type, are candidate vectors for prion propagation. We found a ...

  9. Pluripotent stem cells for the study of CNS development

    Directory of Open Access Journals (Sweden)

    Timothy J. Petros

    2011-10-01

    Full Text Available The mammalian central nervous system is a complex neuronal meshwork consisting of a diverse array of cellular subtypes generated in a precise spatial and temporal pattern throughout development. Achieving a greater understanding of the molecular and genetic mechanisms that direct a relatively uniform population of neuroepithelial progenitors into the diverse neuronal subtypes remains a significant challenge. A firmer knowledge of the fundamental aspects of developmental neuroscience will allow us to better study the vast array of neurodevelopmental diseases. The advent of stem cell technologies has expedited our ability to generate and isolate populations of distinct interneuron subtypes. To date, researchers have successfully developed protocols to derive many types of neural cells from pluripotent stem cells, with varying degrees of efficiencies and reproducibility. The stem cell field is devoted to the potential of stem cell-derived neurons for the treatment of disease, highlighted by the ability to create patient specific induced pluripotent stem cells. However, another application that is often overlooked is the use of stem cell technology for studying normal neural development. This is especially important for human neurodevelopment, since obtaining embryonic tissue presents numerous technical and ethical challenges. In this review, we will explore the use of pluripotent stem cells for the study of neural development. We will review the different classes of pluripotent stem cells and focus on the types of neurodevelopmental questions that stem cell technologies can help address. In addition to covering the different neural cells derived from stem cells to date, we will detail the derivation and characterization of three of the more thoroughly studied cell groups. We hope that this review encourages researchers to develop innovative strategies for using pluripotent stem cells for the study of mammalian, and specifically human

  10. Beta1 integrins differentially control extravasation of inflammatory cell subsets into the CNS during autoimmunity

    DEFF Research Database (Denmark)

    Bauer, Martina; Brakebusch, Cord; Coisne, Caroline;

    2009-01-01

    Inhibiting the alpha(4) subunit of the integrin heterodimers alpha(4)beta(1) and alpha(4)beta(7) with the monoclonal antibody natalizumab is an effective treatment for multiple sclerosis (MS). However, the pharmacological action of natalizumab is not understood conclusively. Previous studies...... suggested that natalizumab inhibits activation, proliferation, or extravasation of inflammatory cells. To specify which mechanisms, cell types, and alpha(4) heterodimers are affected by the antibody treatment, we studied MS-like experimental autoimmune encephalomyelitis (EAE) in mice lacking the beta(1......)-integrin gene either in all hematopoietic cells or selectively in T lymphocytes. Our results show that T cells critically rely on beta(1) integrins to accumulate in the central nervous system (CNS) during EAE, whereas CNS infiltration of beta(1)-deficient myeloid cells remains unaffected, suggesting that T...

  11. Primary CNS Teratocarcinoma

    Directory of Open Access Journals (Sweden)

    Danilo eVitorovic

    2012-02-01

    Full Text Available Primary central nervous system (CNS teratomas are rare tumors that consist of all three germ cell layers. We describe a young man with a primary malignant CNS teratocarcinoma presenting as leptomeningeal carcinomatosis. Diagnosis of primary CNS teratocarcinomas is challenging; relentless pursuit of the diagnosis must follow even if early ancillary studies are inconclusive.

  12. Immune Cell Dynamics in the CNS : Learning From the Zebrafish

    NARCIS (Netherlands)

    Oosterhof, Nynke; Boddeke, Erik; van Ham, Tjakko J.

    2015-01-01

    A major question in research on immune responses in the brain is how the timing and nature of these responses influence physiology, pathogenesis or recovery from pathogenic processes. Proper understanding of the immune regulation of the human brain requires a detailed description of the function and

  13. MALDI mass spectrometry based molecular phenotyping of CNS glial cells for prediction in mammalian brain tissue

    DEFF Research Database (Denmark)

    Hanrieder, Jørg; Wicher, Grzegorz; Bergquist, Jonas;

    2011-01-01

    The development of powerful analytical techniques for specific molecular characterization of neural cell types is of central relevance in neuroscience research for elucidating cellular functions in the central nervous system (CNS). This study examines the use of differential protein expression...... tracers for prediction of oligodendroglial and astroglial localization in brain tissue. The different cell type specific protein distributions in tissue were validated using immunohistochemistry. ICMS of intact neuroglia is a simple and straightforward approach for characterization and discrimination...

  14. Rodent CNS neuron development: Timing of cell birth and death

    Science.gov (United States)

    Keefe, J. R.

    1984-01-01

    Data obtained from a staged series of single paired injections of tritiated thymidine to pregnant Wistar rats or C57B16/j mice on selected embryonic days and several postnatal times are reported. All injected specimens were allowed to come to term, each litter culled to six pups and specimens were sacrificed on PN28, with fixation and embedding for paraffin and plastic embedding. The results are derived from serial paraffin sections of PN28 animals exposed to autoradiographic processing and plotted with respect to heavily labelled cell nuclei present in the selected brain stem nuclei and sensory ganglia. Counts from each time sample/structure are totalled and the percentage of cells in the total labelled population/structure represented by each injection time interval plotted.

  15. Toxicity and in vitro activity of HIV-1 latency-reversing agents in primary CNS cells.

    Science.gov (United States)

    Gray, Lachlan R; On, Hung; Roberts, Emma; Lu, Hao K; Moso, Michael A; Raison, Jacqueline A; Papaioannou, Catherine; Cheng, Wan-Jung; Ellett, Anne M; Jacobson, Jonathan C; Purcell, Damian F J; Wesselingh, Steve L; Gorry, Paul R; Lewin, Sharon R; Churchill, Melissa J

    2016-08-01

    Despite the success of combination antiretroviral therapy (cART), HIV persists in long lived latently infected cells in the blood and tissue, and treatment is required lifelong. Recent clinical studies have trialed latency-reversing agents (LRA) as a method to eliminate latently infected cells; however, the effects of LRA on the central nervous system (CNS), a well-known site of virus persistence on cART, are unknown. In this study, we evaluated the toxicity and potency of a panel of commonly used and well-known LRA (panobinostat, romidepsin, vorinostat, chaetocin, disulfiram, hexamethylene bisacetamide [HMBA], and JQ-1) in primary fetal astrocytes (PFA) as well as monocyte-derived macrophages as a cellular model for brain perivascular macrophages. We show that most LRA are non-toxic in these cells at therapeutic concentrations. Additionally, romidepsin, JQ-1, and panobinostat were the most potent at inducing viral transcription, with greater magnitude observed in PFA. In contrast, vorinostat, chaetocin, disulfiram, and HMBA all demonstrated little or no induction of viral transcription. Together, these data suggest that some LRA could potentially activate transcription in latently infected cells in the CNS. We recommend that future trials of LRA also examine the effects of these agents on the CNS via examination of cerebrospinal fluid.

  16. Toxicity and in vitro activity of HIV-1 latency-reversing agents in primary CNS cells.

    Science.gov (United States)

    Gray, Lachlan R; On, Hung; Roberts, Emma; Lu, Hao K; Moso, Michael A; Raison, Jacqueline A; Papaioannou, Catherine; Cheng, Wan-Jung; Ellett, Anne M; Jacobson, Jonathan C; Purcell, Damian F J; Wesselingh, Steve L; Gorry, Paul R; Lewin, Sharon R; Churchill, Melissa J

    2016-08-01

    Despite the success of combination antiretroviral therapy (cART), HIV persists in long lived latently infected cells in the blood and tissue, and treatment is required lifelong. Recent clinical studies have trialed latency-reversing agents (LRA) as a method to eliminate latently infected cells; however, the effects of LRA on the central nervous system (CNS), a well-known site of virus persistence on cART, are unknown. In this study, we evaluated the toxicity and potency of a panel of commonly used and well-known LRA (panobinostat, romidepsin, vorinostat, chaetocin, disulfiram, hexamethylene bisacetamide [HMBA], and JQ-1) in primary fetal astrocytes (PFA) as well as monocyte-derived macrophages as a cellular model for brain perivascular macrophages. We show that most LRA are non-toxic in these cells at therapeutic concentrations. Additionally, romidepsin, JQ-1, and panobinostat were the most potent at inducing viral transcription, with greater magnitude observed in PFA. In contrast, vorinostat, chaetocin, disulfiram, and HMBA all demonstrated little or no induction of viral transcription. Together, these data suggest that some LRA could potentially activate transcription in latently infected cells in the CNS. We recommend that future trials of LRA also examine the effects of these agents on the CNS via examination of cerebrospinal fluid. PMID:26727904

  17. Immunological assays for chemokine detection in in-vitro culture of CNS cells

    OpenAIRE

    Mahajan Supriya D.; Schwartz Stanley A; Nair Madhavan P.N.

    2003-01-01

    Herein we review the various methods currently in use for determining the expression of chemokines by CNS cells in vitro. Chemokine detection assays are used in conjuction with one another to provide a comprehensive, biologically relevant assessment of the chemokines which is necessary for correct data interpretation of a specific observed biological effect. The methods described include bioassays for soluble chemokine receptors, RNA extraction, RT-PCR, Real - time quantitative PCR, gene arra...

  18. Potency and fate specification in CNS stem cell populations in vitro.

    Science.gov (United States)

    Ravin, Rea; Hoeppner, Daniel J; Munno, David M; Carmel, Liran; Sullivan, Jim; Levitt, David L; Miller, Jennifer L; Athaide, Christopher; Panchision, David M; McKay, Ronald D G

    2008-12-01

    To realize the promise of stem cell biology, it is important to identify the precise time in the history of the cell when developmental potential is restricted. To achieve this goal, we developed a real-time imaging system that captures the transitions in fate, generating neurons, astrocytes, and oligodendrocytes from single CNS stem cells in vitro. In the presence of bFGF, tripotent cells normally produce specified progenitors through a bipotent intermediate cell type. Surprisingly, the tripotent state is reset at each passage. The cytokine CNTF is thought to instruct multipotent cells to an astrocytic fate. We demonstrate that CNTF both directs astrogliogenesis from tripotent cells, bypassing two of the three normal bipotent intermediates, and later promotes the expansion of specified astrocytic progenitors. These results show how discrete cell types emerge from a multipotent cell and provide a strong basis for future studies to determine the molecular basis of fate specification.

  19. Efficient T-cell surveillance of the CNS requires expression of the CXC chemokine receptor 3

    DEFF Research Database (Denmark)

    Christensen, Jeanette Erbo; Nansen, Anneline; Moos, Torben;

    2004-01-01

    T-cells play an important role in controlling viral infections inside the CNS. To study the role of the chemokine receptor CXCR3 in the migration and positioning of virus-specific effector T-cells within the brain, CXCR3-deficient mice were infected intracerebrally with lymphocytic choriomeningitis......-cell-mediated immunopathology. Quantitative analysis of the cellular infiltrate in CSF of infected mice revealed modest, if any, decrease in the number of mononuclear cells recruited to the meninges in the absence of CXCR3. However, immunohistological analysis disclosed a striking impairment of CD8+ T-cells from CXCR3......-deficient mice to migrate from the meninges into the outer layers of the brain parenchyma despite similar localization of virus-infected target cells. Reconstitution of CXCR3-deficient mice with wild-type CD8+ T-cells completely restored susceptibility to LCMV-induced meningitis. Thus, taken together, our...

  20. Microglia roles in healthy Central Nervous System-CNS- (Microglia: ruolo nel Sistema Nervoso Centrale -SNC- integro)

    OpenAIRE

    Maria Luisa Sotgiu

    2014-01-01

    Other than the already known functions on the damaged CNS, data are reported in a recent review, showing that microglial cells have crucial roles on the healthy CNS activity, contributing to its development, neuronal connectivity organization and synaptic plasticity regulation.

  1. Sex bias in CNS autoimmune disease mediated by androgen control of autoimmune regulator.

    Science.gov (United States)

    Zhu, Meng-Lei; Bakhru, Pearl; Conley, Bridget; Nelson, Jennifer S; Free, Meghan; Martin, Aaron; Starmer, Joshua; Wilson, Elizabeth M; Su, Maureen A

    2016-01-01

    Male gender is protective against multiple sclerosis and other T-cell-mediated autoimmune diseases. This protection may be due, in part, to higher androgen levels in males. Androgen binds to the androgen receptor (AR) to regulate gene expression, but how androgen protects against autoimmunity is not well understood. Autoimmune regulator (Aire) prevents autoimmunity by promoting self-antigen expression in medullary thymic epithelial cells, such that developing T cells that recognize these self-antigens within the thymus undergo clonal deletion. Here we show that androgen upregulates Aire-mediated thymic tolerance to protect against autoimmunity. Androgen recruits AR to Aire promoter regions, with consequent enhancement of Aire transcription. In mice and humans, thymic Aire expression is higher in males compared with females. Androgen administration and male gender protect against autoimmunity in a multiple sclerosis mouse model in an Aire-dependent manner. Thus, androgen control of an intrathymic Aire-mediated tolerance mechanism contributes to gender differences in autoimmunity. PMID:27072778

  2. Adeno associated viral-mediated intraosseous labeling of bone marrow derived cells for CNS tracking.

    Science.gov (United States)

    Selenica, Maj-Linda B; Reid, Patrick; Pena, Gabriela; Alvarez, Jennifer; Hunt, Jerry B; Nash, Kevin R; Morgan, Dave; Gordon, Marcia N; Lee, Daniel C

    2016-05-01

    Inflammation, including microglial activation in the CNS, is an important hallmark in many neurodegenerative diseases. Microglial stimuli not only impact the brain microenvironment by production and release of cytokines and chemokines, but also influence the activity of bone marrow derived cells and blood born macrophage populations. In many diseases including brain disorders and spinal cord injury, researchers have tried to harbor the neuroprotective and repair properties of these subpopulations. Hematopoietic bone marrow derived cells (BMDCs) are of great interest, especially during gene therapy because certain hematopoietic cell subpopulations traffic to the sites of injury and inflammation. The aim of this study was to develop a method of labeling endogenous bone marrow derived cells through intraosseous impregnation of recombinant adeno-associated virus (rAAV) or lentivirus. We utilized rAAV serotype 9 (rAAV-9) or lentivirus for gene delivery of green florescence protein (GFP) to the mouse bone marrow cells. Flow cytometry showed that both viruses were able to efficiently transduce mouse bone marrow cells in vivo. However, the rAAV9-GFP viral construct transduced BMDCs more efficiently than the lentivirus (11.2% vs. 6.8%), as indicated by cellular GFP expression. We also demonstrate that GFP labeled cells correspond to bone marrow cells of myeloid origin using CD11b as a marker. Additionally, we characterized the ability of bone marrow derived, GFP labeled cells to extravasate into the brain parenchyma upon acute and subchronic neuroinflammatory stimuli in the mouse CNS. Viral mediated over expression of chemokine (C-C motif) ligand 2 (CCL2) or intracranial injection of lipopolysaccharide (LPS) recruited GFP labeled BMDCs from the periphery into the brain parenchyma compared to vehicle treated mice. Altogether our findings demonstrate a useful method of labeling endogenous BMDCs via viral transduction and the ability to track subpopulations throughout the body

  3. Distinct roles of T-cell lymphopenia and the microbial flora for gastrointestinal and CNS autoimmunity.

    Science.gov (United States)

    Fischer, Henrike J; Witte, Ann-Kathrin; Walter, Lutz; Gröne, Hermann-Josef; van den Brandt, Jens; Reichardt, Holger M

    2016-05-01

    T-cell lymphopenia is a major risk factor for autoimmunity. Here we describe congenic Lewis (LEW) rats with a loss-of-function mutation in the Gimap5 gene, leading to a 92% reduction in peripheral T-cell numbers. Gimap5-deficient LEW rats developed eosinophilic autoimmune gastroenteritis accompanied by a 40-fold increase in IgE serum levels. This phenotype was ameliorated by antibiotic treatment, indicating a critical role of the microbial flora in the development of inflammatory bowel disease. Interestingly, Gimap5-deficient LEW rats showed strongly aggravated experimental autoimmune encephalomyelitis (EAE) after immunization with guinea pig myelin basic protein. This phenotype, however, persisted after antibiosis, confirming that the enhanced CNS autoimmune response in T-cell lymphopenic Gimap5-deficient LEW rats was unrelated to the composition of the microbial flora. Rather, it seems that it was caused by the 7-fold increase in the percentage of activated T cells producing IL-17 and IFN-γ, and the skewed T-cell receptor (TCR) repertoire, both of which were the result of T-cell lymphopenia and not affected by antibiosis. This notion was supported by the observation that adoptive T-cell transfer corrected the TCR repertoire and improved EAE. Collectively, our findings confirm a critical albeit differential role of T-cell lymphopenia in the susceptibility to organ-specific autoimmune responses.-Fischer, H. J., Witte, A.-K., Walter, L., Gröne, H.-J., van den Brandt, J., Reichardt, H. M. Distinct roles of T-cell lymphopenia and the microbial flora for gastrointestinal and CNS autoimmunity. PMID:26740263

  4. CNS progenitor cells and oligodendrocytes are targets of chemotherapeutic agents in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Mayer-Pröschel Margot

    2006-11-01

    Full Text Available Abstract Background Chemotherapy in cancer patients can be associated with serious short- and long-term adverse neurological effects, such as leukoencephalopathy and cognitive impairment, even when therapy is delivered systemically. The underlying cellular basis for these adverse effects is poorly understood. Results We found that three mainstream chemotherapeutic agents – carmustine (BCNU, cisplatin, and cytosine arabinoside (cytarabine, representing two DNA cross-linking agents and an antimetabolite, respectively – applied at clinically relevant exposure levels to cultured cells are more toxic for the progenitor cells of the CNS and for nondividing oligodendrocytes than they are for multiple cancer cell lines. Enhancement of cell death and suppression of cell division were seen in vitro and in vivo. When administered systemically in mice, these chemotherapeutic agents were associated with increased cell death and decreased cell division in the subventricular zone, in the dentate gyrus of the hippocampus and in the corpus callosum of the CNS. In some cases, cell division was reduced, and cell death increased, for weeks after drug administration ended. Conclusion Identifying neural populations at risk during any cancer treatment is of great importance in developing means of reducing neurotoxicity and preserving quality of life in long-term survivors. Thus, as well as providing possible explanations for the adverse neurological effects of systemic chemotherapy, the strong correlations between our in vitro and in vivo analyses indicate that the same approaches we used to identify the reported toxicities can also provide rapid in vitro screens for analyzing new therapies and discovering means of achieving selective protection or targeted killing.

  5. Alectinib's activity against CNS metastases from ALK-positive non-small cell lung cancer: a single institution case series.

    Science.gov (United States)

    Metro, Giulio; Lunardi, Gianluigi; Bennati, Chiara; Chiarini, Pietro; Sperduti, Isabella; Ricciuti, Biagio; Marcomigni, Luca; Costa, Cinzia; Crinò, Lucio; Floridi, Piero; Gori, Stefania; Chiari, Rita

    2016-09-01

    In the present study we assessed the activity of the next-generation anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitor (-TKI) alectinib, in patients with ALK-postive, advanced non-small cell lung cancer (NSCLC) and central nervous system (CNS) metastases. NSCLCs with ALK-positive disease, as assessed by fluorescence in situ hybridization, and CNS metastases were treated with alectinib 600 mg BID. Included patients were followed prospectively in order to evaluate the efficacy of the drug, with particular emphasis on activity in the CNS. Eleven consecutive patients were enrolled. The majority of them were pretreated with crizotinib (n = 10, 90.9 %), and cranial radiotherapy (n = 8, 72.7 %). Six of the seven patients with measurable CNS disease experienced a CNS response, including three patients who were naïve for cranial radiation. Median duration of response was 8 months. For the whole population, median CNS-progression-free survival (-PFS), systemic-PFS, overall-PFS, overall survival, and 1-year survival were 8, 11, 8, 13 months, and 31.1 %, respectively. Two patients experiencing a CNS response were assessed for alectinib's concentrations in serum and cerebro-spinal fluid (CSF), and showed a CSF-to-serum ratio ranging from 0.001 to 0.003 ng/mL. Alectinib is highly active against CNS metastases from ALK-positive NSCLCs, irrespective of prior treatment(s) with ALK-TKI(s) and/or cranial radiotherapy. The low CSF-to-serum ratio of alectinib suggests that measuring the concentrations of the drug in the CSF may not be a reliable surrogate of its distribution into the CNS. PMID:27324494

  6. Ecrg4 expression and its product augurin in the choroid plexus: impact on fetal brain development, cerebrospinal fluid homeostasis and neuroprogenitor cell response to CNS injury

    Directory of Open Access Journals (Sweden)

    Gonzalez Ana

    2011-01-01

    Full Text Available Abstract Background The content and composition of cerebrospinal fluid (CSF is determined in large part by the choroid plexus (CP and specifically, a specialized epithelial cell (CPe layer that responds to, synthesizes, and transports peptide hormones into and out of CSF. Together with ventricular ependymal cells, these CPe relay homeostatic signals throughout the central nervous system (CNS and regulate CSF hydrodynamics. One new candidate signal is augurin, a newly recognized 14 kDa protein that is encoded by esophageal cancer related gene-4 (Ecrg4, a putative tumor suppressor gene whose presence and function in normal tissues remains unexplored and enigmatic. The aim of this study was to explore whether Ecrg4 and its product augurin, can be implicated in CNS development and the response to CNS injury. Methods Ecrg4 gene expression in CNS and peripheral tissues was studied by in situ hybridization and quantitative RT-PCR. Augurin, the protein encoded by Ecrg4, was detected by immunoblotting, immunohistochemistry and ELISA. The biological consequence of augurin over-expression was studied in a cortical stab model of rat CNS injury by intra-cerebro-ventricular injection of an adenovirus vector containing the Ecrg4 cDNA. The biological consequences of reduced augurin expression were evaluated by characterizing the CNS phenotype caused by Ecrg4 gene knockdown in developing zebrafish embryos. Results Gene expression and immunohistochemical analyses revealed that, the CP is a major source of Ecrg4 in the CNS and that Ecrg4 mRNA is predominantly localized to choroid plexus epithelial (CPe, ventricular and central canal cells of the spinal cord. After a stab injury into the brain however, both augurin staining and Ecrg4 gene expression decreased precipitously. If the loss of augurin was circumvented by over-expressing Ecrg4 in vivo, BrdU incorporation by cells in the subependymal zone decreased. Inversely, gene knockdown of Ecrg4 in developing

  7. Potential Therapies by Stem Cell-Derived Exosomes in CNS Diseases: Focusing on the Neurogenic Niche

    Directory of Open Access Journals (Sweden)

    Alejandro Luarte

    2016-01-01

    Full Text Available Neurodegenerative disorders are one of the leading causes of death and disability and one of the biggest burdens on health care systems. Novel approaches using various types of stem cells have been proposed to treat common neurodegenerative disorders such as Alzheimer’s Disease, Parkinson’s Disease, or stroke. Moreover, as the secretome of these cells appears to be of greater benefit compared to the cells themselves, the extracellular components responsible for its therapeutic benefit have been explored. Stem cells, as well as most cells, release extracellular vesicles such as exosomes, which are nanovesicles able to target specific cell types and thus to modify their function by delivering proteins, lipids, and nucleic acids. Exosomes have recently been tested in vivo and in vitro as therapeutic conveyors for the treatment of diseases. As such, they could be engineered to target specific populations of cells within the CNS. Considering the fact that many degenerative brain diseases have an impact on adult neurogenesis, we discuss how the modulation of the adult neurogenic niches may be a therapeutic target of stem cell-derived exosomes. These novel approaches should be examined in cellular and animal models to provide better, more effective, and specific therapeutic tools in the future.

  8. Potential Therapies by Stem Cell-Derived Exosomes in CNS Diseases: Focusing on the Neurogenic Niche

    Science.gov (United States)

    Luarte, Alejandro; Bátiz, Luis Federico; Wyneken, Ursula; Lafourcade, Carlos

    2016-01-01

    Neurodegenerative disorders are one of the leading causes of death and disability and one of the biggest burdens on health care systems. Novel approaches using various types of stem cells have been proposed to treat common neurodegenerative disorders such as Alzheimer's Disease, Parkinson's Disease, or stroke. Moreover, as the secretome of these cells appears to be of greater benefit compared to the cells themselves, the extracellular components responsible for its therapeutic benefit have been explored. Stem cells, as well as most cells, release extracellular vesicles such as exosomes, which are nanovesicles able to target specific cell types and thus to modify their function by delivering proteins, lipids, and nucleic acids. Exosomes have recently been tested in vivo and in vitro as therapeutic conveyors for the treatment of diseases. As such, they could be engineered to target specific populations of cells within the CNS. Considering the fact that many degenerative brain diseases have an impact on adult neurogenesis, we discuss how the modulation of the adult neurogenic niches may be a therapeutic target of stem cell-derived exosomes. These novel approaches should be examined in cellular and animal models to provide better, more effective, and specific therapeutic tools in the future. PMID:27195011

  9. Immunological assays for chemokine detection in in-vitro culture of CNS cells

    Directory of Open Access Journals (Sweden)

    Mahajan Supriya D.

    2003-01-01

    Full Text Available Herein we review the various methods currently in use for determining the expression of chemokines by CNS cells in vitro. Chemokine detection assays are used in conjuction with one another to provide a comprehensive, biologically relevant assessment of the chemokines which is necessary for correct data interpretation of a specific observed biological effect. The methods described include bioassays for soluble chemokine receptors, RNA extraction, RT-PCR, Real - time quantitative PCR, gene array analysis, northern blot analysis, Ribonuclease Protection assay, Flow cytometry, ELISPOT, western blot analysis, and ELISA. No single method of analysis meets the criteria for a comprehensive, biologically relevant assessment of the chemokines, therefore more than one assay might be necessary for correct data interpretation, a choice that is based on development of a scientific rationale for the method with emphasis on the reliability and relevance of the method.

  10. Treatment of splenic marginal zone lymphoma of the CNS with high-dose therapy and allogeneic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Busemann Christoph

    2012-10-01

    Full Text Available Abstract Therapy of indolent lymphomas with involvement of the central nervous system (CNS has not been standardized so far. A 42-year old male patient presented with neurological signs because of leukemic splenic marginal zone lymphoma (SMZL manifested in bone marrow, lymph nodes and CNS. Due to the aggressiveness of the disease and the young age of the patient, an intensive immunochemotherapy followed by high-dose therapy with busulfan, thiotepa and fludarabine and subsequent unrelated allogeneic stem cell transplantation (alloSCT was performed. The haemopoietic stem cells engrafted in time and the patient is doing well (ECOG 0 without evidence for active lymphoma three years after transplantation. Highly sensitive tests by specific quantitative real-time polymerase chain reaction for presence of lymphoma cells in blood and bone marrow indicated also a molecular remission. The reported case shows the feasibility of high-dose therapy and allogeneic stem cell transplantation in high-risk patients with CNS-involvement of indolent non-Hodgkin’s lymphoma. In addition, the case supports the hypothesis that the graft-versus lymphoma effect after alloSCT is also active within the CNS.

  11. Creatine kinase BB and beta-2-microglobulin as markers of CNS metastases in patients with small-cell lung cancer

    DEFF Research Database (Denmark)

    Pedersen, A G; Bach, F W; Nissen, Mogens Holst;

    1985-01-01

    Creatine kinase (CK) and its BB isoenzyme (CK-BB) were measured in CSF in 65 evaluable patients suspected of CNS metastases secondary to small-cell lung cancer (SCLC). In addition, CSF and plasma levels of beta-2-microglobulin (beta-2-m) were measured in a group of 73 evaluable patients. Of the 65...

  12. Transplantation of autologous bone marrow stromal cells (BMSC for CNS disorders – Strategy and tactics for clinical application

    Directory of Open Access Journals (Sweden)

    Satoshi Kuroda

    2010-01-01

    Full Text Available Background – There is increasing evidence that the transplanted bone marrow stromal cells (BMSC significantly promote functional recovery after central nervous system (CNS damage in the animal models of various kinds of CNS disorders, including cerebral infarct, brain contusion and spinal cord injury. However, there are several shortages of information when considering clinical application of BMSC transplantation for patients with neurological disorders. In this paper, therefore, we discuss what we should clarify to establish cell transplantation therapy in clinical situation and describe our recent works for this purpose.Methods and Results – The BMSC have the ability to alter their gene expression profile and phenotype in response to the surrounding circumstances and to protect the neurons by producing some neurotrophic factors. They also promote neurite extension and rebuild the neural circuits in the injured CNS. Using optical imaging and MRI techniques, the transplanted BMSC can non-invasively be tracked in the living animals for at least 8 weeks after transplantation. Functional imaging such as PET scan may have the potential to assess the beneficial effects of BMSC transplantation. The BMSC can be expanded using the animal protein-free culture medium, which would maintain their potential of proliferation, migration, and neural differentiation.Conclusion – It is urgent issues to develop clinical imaging technique to track the transplanted cells in the CNS and evaluate the therapeutic significance of BMSC transplantation in order to establish it as a definite therapeutic strategy in clinical situation in the future

  13. B7-H1 shapes T-cell–mediated brain endothelial cell dysfunction and regional encephalitogenicity in spontaneous CNS autoimmunity

    Science.gov (United States)

    Klotz, Luisa; Kuzmanov, Ivan; Hucke, Stephanie; Gross, Catharina C.; Posevitz, Vilmos; Dreykluft, Angela; Schulte-Mecklenbeck, Andreas; Janoschka, Claudia; Lindner, Maren; Herold, Martin; Schwab, Nicholas; Ludwig-Portugall, Isis; Kurts, Christian; Meuth, Sven G.; Kuhlmann, Tanja; Wiendl, Heinz

    2016-01-01

    Molecular mechanisms that determine lesion localization or phenotype variation in multiple sclerosis are mostly unidentified. Although transmigration of activated encephalitogenic T cells across the blood–brain barrier (BBB) is a crucial step in the disease pathogenesis of CNS autoimmunity, the consequences on brain endothelial barrier integrity upon interaction with such T cells and subsequent lesion formation and distribution are largely unknown. We made use of a transgenic spontaneous mouse model of CNS autoimmunity characterized by inflammatory demyelinating lesions confined to optic nerves and spinal cord (OSE mice). Genetic ablation of a single immune-regulatory molecule in this model [i.e., B7-homolog 1 (B7-H1, PD-L1)] not only significantly increased incidence of spontaneous CNS autoimmunity and aggravated disease course, especially in the later stages of disease, but also importantly resulted in encephalitogenic T-cell infiltration and lesion formation in normally unaffected brain regions, such as the cerebrum and cerebellum. Interestingly, B7-H1 ablation on myelin oligodendrocyte glycoprotein-specific CD4+ T cells, but not on antigen-presenting cells, amplified T-cell effector functions, such as IFN-γ and granzyme B production. Therefore, these T cells were rendered more capable of eliciting cell contact-dependent brain endothelial cell dysfunction and increased barrier permeability in an in vitro model of the BBB. Our findings suggest that a single immune-regulatory molecule on T cells can be ultimately responsible for localized BBB breakdown, and thus substantial changes in lesion topography in the context of CNS autoimmunity. PMID:27671636

  14. Systemic Central Nervous System (CNS)-targeted Delivery of Neuropeptide Y (NPY) Reduces Neurodegeneration and Increases Neural Precursor Cell Proliferation in a Mouse Model of Alzheimer Disease.

    Science.gov (United States)

    Spencer, Brian; Potkar, Rewati; Metcalf, Jeff; Thrin, Ivy; Adame, Anthony; Rockenstein, Edward; Masliah, Eliezer

    2016-01-22

    Neuropeptide Y (NPY) is one of the most abundant protein transmitters in the central nervous system with roles in a variety of biological functions including: food intake, cardiovascular regulation, cognition, seizure activity, circadian rhythms, and neurogenesis. Reduced NPY and NPY receptor expression is associated with numerous neurodegenerative disorders including Alzheimer disease (AD). To determine whether replacement of NPY could ameliorate some of the neurodegenerative and behavioral pathology associated with AD, we generated a lentiviral vector expressing NPY fused to a brain transport peptide (apoB) for widespread CNS delivery in an APP-transgenic (tg) mouse model of AD. The recombinant NPY-apoB effectively reversed neurodegenerative pathology and behavioral deficits although it had no effect on accumulation of Aβ. The subgranular zone of the hippocampus showed a significant increase in proliferation of neural precursor cells without further differentiation into neurons. The neuroprotective and neurogenic effects of NPY-apoB appeared to involve signaling via ERK and Akt through the NPY R1 and NPY R2 receptors. Thus, widespread CNS-targeted delivery of NPY appears to be effective at reversing the neuronal and glial pathology associated with Aβ accumulation while also increasing NPC proliferation. Overall, increased delivery of NPY to the CNS for AD might be an effective therapy especially if combined with an anti-Aβ therapeutic.

  15. Cell-type-specific Jumonji histone demethylase gene expression in the healthy rat CNS: detection by a novel flow cytometry method

    Directory of Open Access Journals (Sweden)

    Stephanie M.C. Smith

    2014-05-01

    Full Text Available Our understanding of how histone demethylation contributes to the regulation of basal gene expression in the brain is largely unknown in any injury model, and especially in the healthy adult brain. Although Jumonji genes are often regulated transcriptionally, cell-specific gene expression of Jumonji histone demethylases in the brain remains poorly understood. Thus, in the present study we profiled the mRNA levels of 26 Jumonji genes in microglia (CD11b+, neurons (NeuN+ and astrocytes (GFAP+ from the healthy adult rat brain. We optimized a method combining a mZBF (modified zinc-based fixative and FCM (flow cytometry to simultaneously sort cells from non-transgenic animals. We evaluated cell-surface, intracellular and nuclear proteins, including histones, as well as messenger- and micro-RNAs in different cell types simultaneously from a single-sorted sample. We found that 12 Jumonji genes were differentially expressed between adult microglia, neurons and astrocytes. While JMJD2D was neuron-restricted, PHF8 and JMJD1C were expressed in all three cell types although the expression was highest in neurons. JMJD3 and JMJD5 were expressed in all cell types, but were highly enriched in microglia; astrocytes had the lowest expression of UTX and JHDM1D. Levels of global H3K27 (H3 lysine 27 methylation varied among cell types and appeared to be lowest in microglia, indicating that differences in basal gene expression of specific Jumonji histone demethylases may contribute to cell-specific gene expression in the CNS (central nervous system. This multiparametric technique will be valuable for simultaneously assaying chromatin modifications and gene regulation in the adult CNS.

  16. Classically and alternatively activated bone marrow derived macrophages differ in cytoskeletal functions and migration towards specific CNS cell types

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    Dijkstra Christine D

    2011-05-01

    Full Text Available Abstract Background Macrophages play an important role in neuroinflammatory diseases such as multiple sclerosis (MS and spinal cord injury (SCI, being involved in both damage and repair. The divergent effects of macrophages might be explained by their different activation status: classically activated (CA/M1, pro-inflammatory, macrophages and alternatively activated (AA/M2, growth promoting, macrophages. Little is known about the effect of macrophages with these phenotypes in the central nervous system (CNS and how they influence pathogenesis. The aim of this study was therefore to determine the characteristics of these phenotypically different macrophages in the context of the CNS in an in vitro setting. Results Here we show that bone marrow derived CA and AA macrophages have a distinct migratory capacity towards medium conditioned by various cell types of the CNS. AA macrophages were preferentially attracted by the low weight ( Conclusion In conclusion, since AA macrophages are more motile and are attracted by NCM, they are prone to migrate towards neurons in the CNS. CA macrophages have a lower motility and a stronger adhesion to ECM. In neuroinflammatory diseases the restricted migration and motility of CA macrophages might limit lesion size due to bystander damage.

  17. The farnesoid-X-receptor in myeloid cells controls CNS autoimmunity in an IL-10-dependent fashion.

    Science.gov (United States)

    Hucke, Stephanie; Herold, Martin; Liebmann, Marie; Freise, Nicole; Lindner, Maren; Fleck, Ann-Katrin; Zenker, Stefanie; Thiebes, Stephanie; Fernandez-Orth, Juncal; Buck, Dorothea; Luessi, Felix; Meuth, Sven G; Zipp, Frauke; Hemmer, Bernhard; Engel, Daniel Robert; Roth, Johannes; Kuhlmann, Tanja; Wiendl, Heinz; Klotz, Luisa

    2016-09-01

    Innate immune responses by myeloid cells decisively contribute to perpetuation of central nervous system (CNS) autoimmunity and their pharmacologic modulation represents a promising strategy to prevent disease progression in Multiple Sclerosis (MS). Based on our observation that peripheral immune cells from relapsing-remitting and primary progressive MS patients exhibited strongly decreased levels of the bile acid receptor FXR (farnesoid-X-receptor, NR1H4), we evaluated its potential relevance as therapeutic target for control of established CNS autoimmunity. Pharmacological FXR activation promoted generation of anti-inflammatory macrophages characterized by arginase-1, increased IL-10 production, and suppression of T cell responses. In mice, FXR activation ameliorated CNS autoimmunity in an IL-10-dependent fashion and even suppressed advanced clinical disease upon therapeutic administration. In analogy to rodents, pharmacological FXR activation in human monocytes from healthy controls and MS patients induced an anti-inflammatory phenotype with suppressive properties including control of effector T cell proliferation. We therefore, propose an important role of FXR in control of T cell-mediated autoimmunity by promoting anti-inflammatory macrophage responses. PMID:27383204

  18. The CNS microvascular pericyte: pericyte-astrocyte crosstalk in the regulation of tissue survival

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    Bonkowski Drew

    2011-01-01

    Full Text Available Abstract The French scientist Charles Benjamin Rouget identified the pericyte nearly 140 years ago. Since that time the role of the pericyte in vascular function has been difficult to elucidate. It was not until the development of techniques to isolate and culture pericytes that scientists have begun to understand the true impact of this unique cell in the maintenance of tissue homeostasis. In the brain the pericyte is an integral cellular component of the blood-brain barrier and, together with other cells of the neurovascular unit (endothelial cells, astrocytes and neurons the pericyte makes fine-tuned regulatory adjustments and adaptations to promote tissue survival. These regulatory changes involve trans-cellular communication networks between cells. In this review we consider evidence for cell-to-cell crosstalk between pericytes and astrocytes during development and in adult brain.

  19. Mycobacterium tuberculosis-infected human monocytes down-regulate microglial MMP-2 secretion in CNS tuberculosis via TNFα, NFκB, p38 and caspase 8 dependent pathways

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    Elkington Paul T

    2011-05-01

    Full Text Available Abstract Tuberculosis (TB of the central nervous system (CNS is a deadly disease characterized by extensive tissue destruction, driven by molecules such as Matrix Metalloproteinase-2 (MMP-2 which targets CNS-specific substrates. In a simplified cellular model of CNS TB, we demonstrated that conditioned medium from Mycobacterium tuberculosis-infected primary human monocytes (CoMTb, but not direct infection, unexpectedly down-regulates constitutive microglial MMP-2 gene expression and secretion by 72.8% at 24 hours, sustained up to 96 hours (P M.tb-infected monocyte-dependent networks paradoxically involves the pro-inflammatory mediators TNF-α, p38 MAP kinase and NFκB in addition to a novel caspase 8-dependent pathway.

  20. Regulation of gap junction channels by infectious agents and inflammation in the CNS

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    Paul eCastellano

    2014-05-01

    Full Text Available Gap junctions are conglomerates of intercellular channels that connect the cytoplasm of two or more cells, and facilitate the transfer of second messengers, small peptides and RNA resulting in metabolic and electrical coordination. In general, loss of gap junctional communication (GJC has been associated with cellular damage and inflammation resulting in compromise of physiological functions. Recently, it has become evident that gap junction channels also play a critical role in the pathogenesis of infectious diseases and associated inflammation. Several pathogens use the transfer of intracellular signals through GJ channels to spread infection and toxic signals that amplify inflammation to neighboring cells. Thus, identification of the mechanisms by which several infectious agents alter GJC could result in new potential therapeutic approaches to reduce inflammation and their pathogenesis.

  1. Axo-Glia Interaction Preceding CNS Myelination Is Regulated by Bidirectional Eph-Ephrin Signaling

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    Cecilie Linneberg

    2015-09-01

    Full Text Available In the central nervous system, myelination of axons is required to ensure fast saltatory conduction and for survival of neurons. However, not all axons are myelinated, and the molecular mechanisms involved in guiding the oligodendrocyte processes toward the axons to be myelinated are not well understood. Only a few negative or positive guidance clues that are involved in regulating axo-glia interaction prior to myelination have been identified. One example is laminin, known to be required for early axo-glia interaction, which functions through α6β1 integrin. Here, we identify the Eph-ephrin family of guidance receptors as novel regulators of the initial axo-glia interaction, preceding myelination. We demonstrate that so-called forward and reverse signaling, mediated by members of both Eph and ephrin subfamilies, has distinct and opposing effects on processes extension and myelin sheet formation. EphA forward signaling inhibits oligodendrocyte process extension and myelin sheet formation, and blocking of bidirectional signaling through this receptor enhances myelination. Similarly, EphB forward signaling also reduces myelin membrane formation, but in contrast to EphA forward signaling, this occurs in an integrin-dependent manner, which can be reversed by overexpression of a constitutive active β1-integrin. Furthermore, ephrin-B reverse signaling induced by EphA4 or EphB1 enhances myelin sheet formation. Combined, this suggests that the Eph-ephrin receptors are important mediators of bidirectional signaling between axons and oligodendrocytes. It further implies that balancing Eph-ephrin forward and reverse signaling is important in the selection process of axons to be myelinated.

  2. Validation of Flow Cytometry and Magnetic Bead-Based Methods to Enrich CNS Single Cell Suspensions for Quiescent Microglia.

    Science.gov (United States)

    Volden, T A; Reyelts, C D; Hoke, T A; Arikkath, J; Bonasera, S J

    2015-12-01

    Microglia are resident mononuclear phagocytes within the CNS parenchyma that intimately interact with neurons and astrocytes to remodel synapses and extracellular matrix. We briefly review studies elucidating the molecular pathways that underlie microglial surveillance, activation, chemotaxis, and phagocytosis; we additionally place these studies in a clinical context. We describe and validate an inexpensive and simple approach to obtain enriched single cell suspensions of quiescent parenchymal and perivascular microglia from the mouse cerebellum and hypothalamus. Following preparation of regional CNS single cell suspensions, we remove myelin debris, and then perform two serial enrichment steps for cells expressing surface CD11b. Myelin depletion and CD11b enrichment are both accomplished using antigen-specific magnetic beads in an automated cell separation system. Flow cytometry of the resultant suspensions shows a significant enrichment for CD11b(+)/CD45(+) cells (perivascular microglia) and CD11b(+)/CD45(-) cells (parenchymal microglia) compared to starting suspensions. Of note, cells from these enriched suspensions minimally express Aif1 (aka Iba1), suggesting that the enrichment process does not evoke significant microglial activation. However, these cells readily respond to a functional challenge (LPS) with significant changes in the expression of molecules specifically associated with microglia. We conclude that methods employing a combination of magnetic-bead based sorting and flow cytometry produce suspensions highly enriched for microglia that are appropriate for a variety of molecular and cellular assays.

  3. Distinctive response of CNS glial cells in oro-facial pain associated with injury, infection and inflammation.

    Science.gov (United States)

    Lee, SeungHwan; Zhao, Yuan Qing; Ribeiro-da-Silva, Alfredo; Zhang, Ji

    2010-01-01

    Oro-facial pain following injury and infection is frequently observed in dental clinics. While neuropathic pain evoked by injury associated with nerve lesion has an involvement of glia/immune cells, inflammatory hyperalgesia has an exaggerated sensitization mediated by local and circulating immune mediators. To better understand the contribution of central nervous system (CNS) glial cells in these different pathological conditions, in this study we sought to characterize functional phenotypes of glial cells in response to trigeminal nerve injury (loose ligation of the mental branch), infection (subcutaneous injection of lipopolysaccharide--LPS) and to sterile inflammation (subcutaneous injection of complete Freund's adjuvant--CFA) on the lower lip. Each of the three insults triggered a specific pattern of mechanical allodynia. In parallel with changes in sensory response, CNS glial cells reacted distinctively to the challenges. Following ligation of the mental nerve, both microglia and astrocytes in the trigeminal nuclear complex were highly activated, more prominent in the principal sensory nucleus (Pr5) and subnucleus caudalis (Sp5C) area. Microglial response was initiated early (days 3-14), followed by delayed astrocytes activation (days 7-28). Although the temporal profile of microglial and astrocyte reaction corresponded respectively to the initiation and chronic stage of neuropathic pain, these activated glial cells exhibited a low profile of cytokine expression. Local injection of LPS in the lower lip skin also triggered a microglial reaction in the brain, which started in the circumventricular organs (CVOs) at 5 hours post-injection and diffused progressively into the brain parenchyma at 48 hours. This LPS-induced microglial reaction was accompanied by a robust induction of IκB-α mRNA and pro-inflammatory cytokines within the CVOs. However, LPS induced microglial activation did not specifically occur along the pain signaling pathway. In contrast, CFA

  4. Distinctive response of CNS glial cells in oro-facial pain associated with injury, infection and inflammation

    Directory of Open Access Journals (Sweden)

    Ribeiro-da-Silva Alfredo

    2010-11-01

    Full Text Available Abstract Oro-facial pain following injury and infection is frequently observed in dental clinics. While neuropathic pain evoked by injury associated with nerve lesion has an involvement of glia/immune cells, inflammatory hyperalgesia has an exaggerated sensitization mediated by local and circulating immune mediators. To better understand the contribution of central nervous system (CNS glial cells in these different pathological conditions, in this study we sought to characterize functional phenotypes of glial cells in response to trigeminal nerve injury (loose ligation of the mental branch, infection (subcutaneous injection of lipopolysaccharide-LPS and to sterile inflammation (subcutaneous injection of complete Freund's adjuvant-CFA on the lower lip. Each of the three insults triggered a specific pattern of mechanical allodynia. In parallel with changes in sensory response, CNS glial cells reacted distinctively to the challenges. Following ligation of the mental nerve, both microglia and astrocytes in the trigeminal nuclear complex were highly activated, more prominent in the principal sensory nucleus (Pr5 and subnucleus caudalis (Sp5C area. Microglial response was initiated early (days 3-14, followed by delayed astrocytes activation (days 7-28. Although the temporal profile of microglial and astrocyte reaction corresponded respectively to the initiation and chronic stage of neuropathic pain, these activated glial cells exhibited a low profile of cytokine expression. Local injection of LPS in the lower lip skin also triggered a microglial reaction in the brain, which started in the circumventricular organs (CVOs at 5 hours post-injection and diffused progressively into the brain parenchyma at 48 hours. This LPS-induced microglial reaction was accompanied by a robust induction of IκB-α mRNA and pro-inflammatory cytokines within the CVOs. However, LPS induced microglial activation did not specifically occur along the pain signaling pathway. In

  5. T-cells in the cerebrospinal fluid express a similar repertoire of inflammatory chemokine receptors in the absence or presence of CNS inflammation

    DEFF Research Database (Denmark)

    Kivisäkk, P; Trebst, C; Liu, Z;

    2002-01-01

    It is believed that chemokines and their receptors are involved in trafficking of T-cells to the central nervous system (CNS). The aim of the current study was to define the expression on cerebrospinal fluid (CSF) T-cells of six chemokine receptors associated with trafficking to sites...... is not sufficient for the trafficking of CD3+T-cells to the CSF. We hypothesize that CXCR3 is the principal inflammatory chemokine receptor involved in intrathecal accumulation of T-cells in MS. Through interactions with its ligands, CXCR3 is proposed to mediate retention of T-cells in the inflamed CNS....

  6. NCAM regulates cell motility

    DEFF Research Database (Denmark)

    Prag, Søren; Lepekhin, Eugene A; Kolkova, Kateryna;

    2002-01-01

    Cell migration is required during development of the nervous system. The regulatory mechanisms for this process, however, are poorly elucidated. We show here that expression of or exposure to the neural cell adhesion molecule (NCAM) strongly affected the motile behaviour of glioma cells...... independently of homophilic NCAM interactions. Expression of the transmembrane 140 kDa isoform of NCAM (NCAM-140) caused a significant reduction in cellular motility, probably through interference with factors regulating cellular attachment, as NCAM-140-expressing cells exhibited a decreased attachment...... to a fibronectin substratum compared with NCAM-negative cells. Ectopic expression of the cytoplasmic part of NCAM-140 also inhibited cell motility, presumably via the non-receptor tyrosine kinase p59(fyn) with which NCAM-140 interacts. Furthermore, we showed that the extracellular part of NCAM acted as a paracrine...

  7. STARs in the CNS.

    Science.gov (United States)

    Ehrmann, Ingrid; Fort, Philippe; Elliott, David J

    2016-08-15

    STAR (signal transduction and activation of RNA) proteins regulate splicing of target genes that have roles in neural connectivity, survival and myelination in the vertebrate nervous system. These regulated splicing targets include mRNAs such as the Neurexins (Nrxn), SMN2 (survival of motor neuron) and MAG (myelin-associated glycoprotein). Recent work has made it possible to identify and validate STAR protein splicing targets in vivo by using genetically modified mouse models. In this review, we will discuss the importance of STAR protein splicing targets in the CNS (central nervous system). PMID:27528753

  8. Laminin-411 is a vascular ligand for MCAM and facilitates TH17 cell entry into the CNS.

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    Ken Flanagan

    Full Text Available TH17 cells enter tissues to facilitate pathogenic autoimmune responses, including multiple sclerosis (MS. However, the adhesion molecules involved in the unique migratory capacity of TH17 cells, into both inflamed and uninflamed tissues remain unclear. Herein, we characterize MCAM (CD146 as an adhesion molecule that defines human TH17 cells in the circulation; following in vitro restimulation of human memory T cells, nearly all of the capacity to secrete IL-17 is contained within the population of cells expressing MCAM. Furthermore, we identify the MCAM ligand as laminin 411, an isoform of laminin expressed within the vascular endothelial basement membranes under inflammatory as well as homeotstatic conditions. Purified MCAM-Fc binds to laminin 411 with an affinity of 27 nM, and recognizes vascular basement membranes in mouse and human tissue. MCAM-Fc binding was undetectable in tissue from mice with targeted deletion of laminin 411, indicating that laminin 411 is a major tissue ligand for MCAM. An anti-MCAM monoclonal antibody, selected for inhibition of laminin binding, as well as soluble MCAM-Fc, inhibited T cell adhesion to laminin 411 in vitro. When administered in vivo, the antibody reduced TH17 cell infiltration into the CNS and ameliorated disease in an animal model of MS. Our data suggest that MCAM and laminin 411 interact to facilitate TH17 cell entry into tissues and promote inflammation.

  9. Histological characterization and quantification of cellular events following neural and fibroblast(-like) stem cell grafting in healthy and demyelinated CNS tissue.

    Science.gov (United States)

    Praet, Jelle; Santermans, Eva; Reekmans, Kristien; de Vocht, Nathalie; Le Blon, Debbie; Hoornaert, Chloé; Daans, Jasmijn; Goossens, Herman; Berneman, Zwi; Hens, Niel; Van der Linden, Annemie; Ponsaerts, Peter

    2014-01-01

    Preclinical animal studies involving intracerebral (stem) cell grafting are gaining popularity in many laboratories due to the reported beneficial effects of cell grafting on various diseases or traumata of the central nervous system (CNS). In this chapter, we describe a histological workflow to characterize and quantify cellular events following neural and fibroblast(-like) stem cell grafting in healthy and demyelinated CNS tissue. First, we provide standardized protocols to isolate and culture eGFP(+) neural and fibroblast(-like) stem cells from embryonic mouse tissue. Second, we describe flow cytometric procedures to determine cell viability, eGFP transgene expression, and the expression of different stem cell lineage markers. Third, we explain how to induce reproducible demyelination in the CNS of mice by means of cuprizone administration, a validated mouse model for human multiple sclerosis. Fourth, the technical procedures for cell grafting in the CNS are explained in detail. Finally, an optimized and validated workflow for the quantitative histological analysis of cell graft survival and endogenous astroglial and microglial responses is provided. PMID:25173390

  10. Evaluation of cell proliferation, apoptosis, and dna-repair genes as potential biomarkers for ethanol-induced cns alterations

    Directory of Open Access Journals (Sweden)

    Hicks Steven D

    2012-10-01

    Full Text Available Abstract Background Alcohol use disorders (AUDs lead to alterations in central nervous system (CNS architecture along with impaired learning and memory. Previous work from our group and that of others suggests that one mechanism underlying these changes is alteration of cell proliferation, apoptosis, and DNA-repair in neural stem cells (NSCs produced as a consequence of ethanol-induced effects on the expression of genes related to p53-signaling. This study tests the hypothesis that changes in the expression of p53-signaling genes represent biomarkers of ethanol abuse which can be identified in the peripheral blood of rat drinking models and human AUD subjects and posits that specific changes may be correlated with differences in neuropsychological measures and CNS structure. Results Remarkably, microarray analysis of 350 genes related to p53-signaling in peripheral blood leukocytes (PBLs of binge-drinking rats revealed 190 genes that were significantly altered after correcting for multiple testing. Moreover, 40 of these genes overlapped with those that we had previously observed to be changed in ethanol-exposed mouse NSCs. Expression changes in nine of these genes were tested for independent confirmation by a custom QuantiGene Plex (QGP assay for a subset of p53-signaling genes, where a consistent trend for decreased expression of mitosis-related genes was observed. One mitosis-related gene (Pttg1 was also changed in human lymphoblasts cultured with ethanol. In PBLs of human AUD subjects seven p53-signaling genes were changed compared with non-drinking controls. Correlation and principal components analysis were then used to identify significant relationships between the expression of these seven genes and a set of medical, demographic, neuropsychological and neuroimaging measures that distinguished AUD and control subjects. Two genes (Ercc1 and Mcm5 showed a highly significant correlation with AUD-induced decreases in the volume of the left

  11. Inhibition of phosphodiesterase-4 promotes oligodendrocyte precursor cell differentiation and enhances CNS remyelination.

    Science.gov (United States)

    Syed, Yasir A; Baer, Alexandra; Hofer, Matthias P; González, Ginez A; Rundle, Jon; Myrta, Szymon; Huang, Jeffrey K; Zhao, Chao; Rossner, Moritz J; Trotter, Matthew W B; Lubec, Gert; Franklin, Robin J M; Kotter, Mark R

    2013-12-01

    The increasing effectiveness of new disease-modifying drugs that suppress disease activity in multiple sclerosis has opened up opportunities for regenerative medicines that enhance remyelination and potentially slow disease progression. Although several new targets for therapeutic enhancement of remyelination have emerged, few lend themselves readily to conventional drug development. Here, we used transcription profiling to identify mitogen-activated protein kinase (Mapk) signalling as an important regulator involved in the differentiation of oligodendrocyte progenitor cells (OPCs) into oligodendrocytes. We show in tissue culture that activation of Mapk signalling by elevation of intracellular levels of cyclic adenosine monophosphate (cAMP) using administration of either dibutyryl-cAMP or inhibitors of the cAMP-hydrolysing enzyme phosphodiesterase-4 (Pde4) enhances OPC differentiation. Finally, we demonstrate that systemic delivery of a Pde4 inhibitor leads to enhanced differentiation of OPCs within focal areas of toxin-induced demyelination and a consequent acceleration of remyelination. These data reveal a novel approach to therapeutic enhancement of remyelination amenable to pharmacological intervention and hence with significant potential for translation. PMID:24293318

  12. Highly encephalitogenic aquaporin 4-specific T cells and NMO-IgG jointly orchestrate lesion location and tissue damage in the CNS

    DEFF Research Database (Denmark)

    Zeka, Bleranda; Hastermann, Maria; Hochmeister, Sonja;

    2015-01-01

    In neuromyelitis optica (NMO), astrocytes become targets for pathogenic aquaporin 4 (AQP4)-specific antibodies which gain access to the central nervous system (CNS) in the course of inflammatory processes. Since these antibodies belong to a T cell-dependent subgroup of immunoglobulins, and since...

  13. Aquaporin-4 in Astroglial Cells in the CNS and Supporting Cells of Sensory Organs—A Comparative Perspective

    Directory of Open Access Journals (Sweden)

    Corinna Gleiser

    2016-08-01

    Full Text Available The main water channel of the brain, aquaporin-4 (AQP4, is one of the classical water-specific aquaporins. It is expressed in many epithelial tissues in the basolateral membrane domain. It is present in the membranes of supporting cells in most sensory organs in a specifically adapted pattern: in the supporting cells of the olfactory mucosa, AQP4 occurs along the basolateral aspects, in mammalian retinal Müller cells it is highly polarized. In the cochlear epithelium of the inner ear, it is expressed basolaterally in some cells but strictly basally in others. Within the central nervous system, aquaporin-4 (AQP4 is expressed by cells of the astroglial family, more specifically, by astrocytes and ependymal cells. In the mammalian brain, AQP4 is located in high density in the membranes of astrocytic endfeet facing the pial surface and surrounding blood vessels. At these locations, AQP4 plays a role in the maintenance of ionic homeostasis and volume regulation. This highly polarized expression has not been observed in the brain of fish where astroglial cells have long processes and occur mostly as radial glial cells. In the brain of the zebrafish, AQP4 immunoreactivity is found along the radial extent of astroglial cells. This suggests that the polarized expression of AQP4 was not present at all stages of evolution. Thus, a polarized expression of AQP4 as part of a control mechanism for a stable ionic environment and water balanced occurred at several locations in supporting and glial cells during evolution. This initially basolateral membrane localization of AQP4 is shifted to highly polarized expression in astrocytic endfeet in the mammalian brain and serves as a part of the neurovascular unit to efficiently maintain homeostasis.

  14. T-bet expression by Foxp3+ T regulatory cells is not essential for their suppressive function in CNS autoimmune disease or colitis

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    Rhoanne C McPherson

    2015-02-01

    Full Text Available Accumulation of T regulatory (Treg cells within the central nervous system (CNS during experimental autoimmune encephalomyelitis (EAE is essential for the resolution of disease. CNS Treg cells have been shown to uniformly express the Th1-associated molecules T-bet and CXCR3. Here we report that the expression of T-bet is not required for the function of these Treg within the CNS. Using mice that lacked T-bet expression specifically within the Treg compartment, we demonstrate that there was no deficit in Treg recruitment into the CNS during EAE and no difference in the resolution of disease compared to control mice. T-bet deficiency did not impact on the in vitro suppressive capacity of Treg. Transfer of T-bet-deficient Treg was able to suppress clinical signs of either EAE, or colitis. These observations demonstrate that, although Treg can acquire characteristics associated with pathogenic Teff cells, this process is not necessarily required for their suppressive capacity and the resolution of autoimmune inflammation.

  15. Potential Therapies by Stem Cell-Derived Exosomes in CNS Diseases: Focusing on the Neurogenic Niche

    OpenAIRE

    Luarte, Alejandro; Bátiz, Luis Federico; Wyneken, Ursula; Lafourcade, Carlos

    2016-01-01

    Neurodegenerative disorders are one of the leading causes of death and disability and one of the biggest burdens on health care systems. Novel approaches using various types of stem cells have been proposed to treat common neurodegenerative disorders such as Alzheimer's Disease, Parkinson's Disease, or stroke. Moreover, as the secretome of these cells appears to be of greater benefit compared to the cells themselves, the extracellular components responsible for its therapeutic benefit have be...

  16. Potential Therapies by Stem Cell-Derived Exosomes in CNS Diseases: Focusing on the Neurogenic Niche

    OpenAIRE

    Luarte, Alejandro; Bátiz, Luis Federico; Wyneken, Ursula; Lafourcade, Carlos

    2016-01-01

    Neurodegenerative disorders are one of the leading causes of death and disability and one of the biggest burdens on health care systems. Novel approaches using various types of stem cells have been proposed to treat common neurodegenerative disorders such as Alzheimer’s Disease, Parkinson’s Disease, or stroke. Moreover, as the secretome of these cells appears to be of greater benefit compared to the cells themselves, the extracellular components responsible for its therapeutic benefit have be...

  17. Role of Microfluidics in Blood-Brain Barrier Permeability Cell Culture Modeling: Relevance to CNS Disorders.

    Science.gov (United States)

    Rusanov, Alexander L; Luzgina, Natalia G; Barreto, George E; Aliev, Gjumrakch

    2016-01-01

    In vitro modeling of the human blood-brain barrier (BBB) is critical for pre-clinical evaluation and predicting the permeability of newly developed potentially neurotoxic and neurotrophic drugs. Here we summarize the specific structural and functional features of endothelial cells as a key component of the BBB and compare analysis of different cell culture models in reflecting these features. Particular attention is paid to cellular models of the BBB in microfluidic devices capable of circulating nutrient media to simulate the blood flow of the brain. In these conditions, it is possible to reproduce a number of factors affecting endothelial cells under physiological conditions, including shear stress. In comparison with static cell models, concentration gradients, which determine the velocity of transport of substances, reproduce more accurately conditions of nutrient medium flow, since they eliminate the accumulation of substances near the basal membrane of cells, not typical for the situation in vivo. Co-cultivation of different types of cells forming the BBB, in separate cell chambers connected by microchannels, allows to evaluate the mutual influences of cells under normal conditions and when exposed to the test substance. New experimental possibilities that can be achieved through modeling of BBB in microfluidic devices determine the feasibility of their use in the practice for pre-clinical studies of novel drugs against neurodegenerative diseases. PMID:26831260

  18. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  19. Neutrophils that infiltrate the central nervous system regulate T cell responses

    DEFF Research Database (Denmark)

    Zehntner, Simone P; Brickman, Cristina; Bourbonnière, Lyne;

    2005-01-01

    Regulation of inflammatory responses is critical to progression of organ-specific autoimmune disease. Although many candidate cell types have been identified, immunoregulatory activity has rarely been directly assayed and never from the CNS. We have analyzed the regulatory capability of Gr-1high ...

  20. Street-Experienced Peripheral B cells Traffic to the CNS in Multiple Sclerosis

    OpenAIRE

    Lu, Daniel R.; Robinson, William H

    2014-01-01

    High-throughput sequencing of immunoglobulin repertoires in patients with multiple sclerosis reveals that antigen-experienced B cells traffic between the peripheral lymph nodes and the central nervous system, suggesting the involvement of peripheral immunity in the autoimmune pathogenesis of multiple sclerosis.

  1. Proteomic studies of a single CNS synapse type: the parallel fiber/purkinje cell synapse.

    Directory of Open Access Journals (Sweden)

    Fekrije Selimi

    2009-04-01

    Full Text Available Precise neuronal networks underlie normal brain function and require distinct classes of synaptic connections. Although it has been shown that certain individual proteins can localize to different classes of synapses, the biochemical composition of specific synapse types is not known. Here, we have used a combination of genetically engineered mice, affinity purification, and mass spectrometry to profile proteins at parallel fiber/Purkinje cell synapses. We identify approximately 60 candidate postsynaptic proteins that can be classified into 11 functional categories. Proteins involved in phospholipid metabolism and signaling, such as the protein kinase MRCKgamma, are major unrecognized components of this synapse type. We demonstrate that MRCKgamma can modulate maturation of dendritic spines in cultured cortical neurons, and that it is localized specifically to parallel fiber/Purkinje cell synapses in vivo. Our data identify a novel synapse-specific signaling pathway, and provide an approach for detailed investigations of the biochemical complexity of central nervous system synapse types.

  2. Neuron-NG2 Cell Synapses: Novel Functions for Regulating NG2 Cell Proliferation and Differentiation

    Directory of Open Access Journals (Sweden)

    Qian-Kun Yang

    2013-01-01

    Full Text Available NG2 cells are a population of CNS cells that are distinct from neurons, mature oligodendrocytes, astrocytes, and microglia. These cells can be identified by their NG2 proteoglycan expression. NG2 cells have a highly branched morphology, with abundant processes radiating from the cell body, and express a complex set of voltage-gated channels, AMPA/kainate, and GABA receptors. Neurons notably form classical and nonclassical synapses with NG2 cells, which have varied characteristics and functions. Neuron-NG2 cell synapses could fine-tune NG2 cell activities, including the NG2 cell cycle, differentiation, migration, and myelination, and may be a novel potential therapeutic target for NG2 cell-related diseases, such as hypoxia-ischemia injury and periventricular leukomalacia. Furthermore, neuron-NG2 cell synapses may be correlated with the plasticity of CNS in adulthood with the synaptic contacts passing onto their progenies during proliferation, and synaptic contacts decrease rapidly upon NG2 cell differentiation. In this review, we highlight the characteristics of classical and nonclassical neuron-NG2 cell synapses, the potential functions, and the fate of synaptic contacts during proliferation and differentiation, with the emphasis on the regulation of the NG2 cell cycle by neuron-NG2 cell synapses and their potential underlying mechanisms.

  3. CNS Hodgkin lymphoma

    OpenAIRE

    Gerstner, Elizabeth R.; Abrey, Lauren E.; Schiff, David; Ferreri, Andrés J. M; Lister, Andrew; Montoto, Silvia; Tsang, Richard; Thiel, Eckhard; Graus, Francesc; Behringer, Dirk; Illerhaus, Gerald; Weaver, Susan; Wen, Patrick; Voloschin, Alfredo; Harris, Nancy Lee

    2008-01-01

    Central nervous system (CNS) involvement by Hodgkin lymphoma (HL) is rare. As a result, there is limited guidance for clinicians on how to manage these patients. Detailed information was collected on 16 patients, the largest number to date, with meningeal or parenchymal CNS-HL confirmed by histopathology (15) or CSF (1). Eight patients presented with CNS-HL at diagnosis, 2 of whom had isolated CNS disease, while 8 patients developed CNS-HL at relapse. Patients received a range of treatments i...

  4. IL-2 suppression of IL-12p70 by a recombinant HSV-1 expressing IL-2 induces T-cell auto-reactivity and CNS demyelination.

    Directory of Open Access Journals (Sweden)

    Mandana Zandian

    Full Text Available To evaluate the role of cellular infiltrates in CNS demyelination in immunocompetent mice, we have used a model of multiple sclerosis (MS in which different strains of mice are infected with a recombinant HSV-1 expressing IL-2. Histologic examination of the mice infected with HSV-IL-2 demonstrates that natural killer cells, dendritic cells, B cells, and CD25 (IL-2rα do not play any role in the HSV-IL-2-induced demyelination. T cell depletion, T cell knockout and T cell adoptive transfer experiments suggest that both CD8(+ and CD4(+ T cells contribute to HSV-IL-2-induced CNS demyelination with CD8(+ T cells being the primary inducers. In the adoptive transfer studies, all of the transferred T cells irrespective of their CD25 status at the time of transfer were positive for expression of FoxP3 and depletion of FoxP3 blocked CNS demyelination by HSV-IL-2. The expression levels of IL-12p35 relative to IL-12p40 differed in BM-derived macrophages infected with HSV-IL-2 from those infected with wild-type HSV-1. HSV-IL-2-induced demyelination was blocked by injecting HSV-IL-2-infected mice with IL-12p70 DNA. This study demonstrates that suppression of the IL-12p70 function of macrophages by IL-2 causes T cells to become auto-aggressive. Interruption of this immunoregulatory axis results in demyelination of the optic nerve, the spinal cord and the brain by autoreactive T cells in the HSV-IL-2 mouse model of MS.

  5. Glucocorticoid treatment of MCMV infected newborn mice attenuates CNS inflammation and limits deficits in cerebellar development.

    Directory of Open Access Journals (Sweden)

    Kate Kosmac

    2013-03-01

    Full Text Available Infection of the developing fetus with human cytomegalovirus (HCMV is a major cause of central nervous system disease in infants and children; however, mechanism(s of disease associated with this intrauterine infection remain poorly understood. Utilizing a mouse model of HCMV infection of the developing CNS, we have shown that peripheral inoculation of newborn mice with murine CMV (MCMV results in CNS infection and developmental abnormalities that recapitulate key features of the human infection. In this model, animals exhibit decreased granule neuron precursor cell (GNPC proliferation and altered morphogenesis of the cerebellar cortex. Deficits in cerebellar cortical development are symmetric and global even though infection of the CNS results in a non-necrotizing encephalitis characterized by widely scattered foci of virus-infected cells with mononuclear cell infiltrates. These findings suggested that inflammation induced by MCMV infection could underlie deficits in CNS development. We investigated the contribution of host inflammatory responses to abnormal cerebellar development by modulating inflammatory responses in infected mice with glucocorticoids. Treatment of infected animals with glucocorticoids decreased activation of CNS mononuclear cells and expression of inflammatory cytokines (TNF-α, IFN-β and IFNγ in the CNS while minimally impacting CNS virus replication. Glucocorticoid treatment also limited morphogenic abnormalities and normalized the expression of developmentally regulated genes within the cerebellum. Importantly, GNPC proliferation deficits were normalized in MCMV infected mice following glucocorticoid treatment. Our findings argue that host inflammatory responses to MCMV infection contribute to deficits in CNS development in MCMV infected mice and suggest that similar mechanisms of disease could be responsible for the abnormal CNS development in human infants infected in-utero with HCMV.

  6. Metallothionein expression and roles in the CNS

    DEFF Research Database (Denmark)

    Penkowa, Milena

    2002-01-01

    -I+II) are regulated and expressed coordinately and are currently the best characterized MT isoforms. This review will focus on the expression and roles of MT-I+II in the CNS. MT-I+II are implicated in diverse physiological and pathophysiological functions, such as metal ion metabolism, regulation of the CNS...... mortality and clinical symptoms are altogether significantly increased in MT-I+II deficient mice, while the opposite is observed after medical MT-II treatment and in MT-I overexpressing mice. Consequently, MT-I+II are likely essential factors during CNS disorders, which suggests a potential therapeutic use...

  7. Negative regulators of cell proliferation

    Science.gov (United States)

    Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Cell proliferation is governed by the influence of both mitogens and inhibitors. Although cell contact has long been thought to play a fundamental role in cell cycling regulation, and negative regulators have long been suspected to exist, their isolation and purification has been complicated by a variety of technical difficulties. Nevertheless, over recent years an ever-expanding list of putative negative regulators have emerged. In many cases, their biological inhibitory activities are consistent with density-dependent growth inhibition. Most likely their interactions with mitogenic agents, at an intracellular level, are responsible for either mitotic arrest or continued cell cycling. A review of naturally occurring cell growth inhibitors is presented with an emphasis on those factors shown to be residents of the cell surface membrane. Particular attention is focused on a cell surface sialoglycopeptide, isolated from intact bovine cerebral cortex cells, which has been shown to inhibit the proliferation of an unusually wide range of target cells. The glycopeptide arrest cells obtained from diverse species, both fibroblasts and epithelial cells, and a broad variety of transformed cells. Signal transduction events and a limited spectrum of cells that are refractory to the sialoglycopeptide have provided insight into the molecular events mediated by this cell surface inhibitor.

  8. Early Inflammatory Responses Following Cell Grafting in the CNS Trigger Activation of the Subventricular Zone: A Proposed Model of Sequential Cellular Events.

    Science.gov (United States)

    Praet, Jelle; Santermans, Eva; Daans, Jasmijn; Le Blon, Debbie; Hoornaert, Chloé; Goossens, Herman; Hens, Niel; Van der Linden, Annemie; Berneman, Zwi; Ponsaerts, Peter

    2015-01-01

    While multiple rodent preclinical studies, and to a lesser extent human clinical trials, claim the feasibility, safety, and potential clinical benefit of cell grafting in the central nervous system (CNS), currently only little convincing knowledge exists regarding the actual fate of the grafted cells and their effect on the surrounding environment (or vice versa). Our preceding studies already indicated that only a minor fraction of the initially grafted cell population survives the grafting process, while the surviving cell population becomes invaded by highly activated microglia/macrophages and surrounded by reactive astrogliosis. In the current study, we further elaborate on early cellular and inflammatory events following syngeneic grafting of eGFP(+) mouse embryonic fibroblasts (mEFs) in the CNS of immunocompetent mice. Based on obtained quantitative histological data, we here propose a detailed mathematically derived working model that sequentially comprises hypoxia-induced apoptosis of grafted mEFs, neutrophil invasion, neoangiogenesis, microglia/macrophage recruitment, astrogliosis, and eventually survival of a limited number of grafted mEFs. Simultaneously, we observed that the cellular events following mEF grafting activates the subventricular zone neural stem and progenitor cell compartment. This proposed model therefore further contributes to our understanding of cell graft-induced cellular responses and will eventually allow for successful manipulation of this intervention.

  9. 1,25-dihydroxyvitamin D3 conditioned CD11c+ dendritic cells are effective initiators of CNS autoimmune disease

    Directory of Open Access Journals (Sweden)

    Dario eBesusso

    2015-11-01

    Full Text Available Dendritic cells (DC play a crucial role in regulating T cell activation. Due to their capacity to shape the immune response, tolerogenic DC have been used to treat autoimmune diseases. In this study we examined whether 1,25 dihydroxyvitamin D3 conditioned bone marrow derived DC (VitD-BMDC were able to limit the development of autoimmune pathology in experimental autoimmune encephalomyelitis (EAE. We found that VitD-BMDC had lower expression of MHC class II and co-stimulatory molecules and were less effective at priming autoreactive T cells in-vitro. Using our recently described BMDC driven model of EAE, we demonstrated that VitD-BMDC had a significantly reduced ability to initiate EAE. We found that the impaired ability of VitD-BMDC to initiate EAE was not due to T cell tolerisation. Instead, we discovered that the addition of 1,25(OH2D3 to BMDC cultures resulted in a significant reduction in the proportion of CD11c+ cells. Purified CD11c+VitD-BMDC were significantly less effective at priming T cells in-vitro yet were similarly capable of initiating EAE as vehicle treated CD11c+BMDC. This study demonstrates that in-vitro assays of DC function can be a poor predictor of in-vivo behaviour and that CD11c+VitD-BMDC are highly effective initiators of an autopathogenic T cell response.

  10. Changes in microtubule stability and density in myelin-deficient shiverer mouse CNS axons

    Science.gov (United States)

    Kirkpatrick, L. L.; Witt, A. S.; Payne, H. R.; Shine, H. D.; Brady, S. T.

    2001-01-01

    Altered axon-Schwann cell interactions in PNS myelin-deficient Trembler mice result in changed axonal transport rates, neurofilament and microtubule-associated protein phosphorylation, neurofilament density, and microtubule stability. To determine whether PNS and CNS myelination have equivalent effects on axons, neurofilaments, and microtubules in CNS, myelin-deficient shiverer axons were examined. The genetic defect in shiverer is a deletion in the myelin basic protein (MBP) gene, an essential component of CNS myelin. As a result, shiverer mice have little or no compact CNS myelin. Slow axonal transport rates in shiverer CNS axons were significantly increased, in contrast to the slowing in demyelinated PNS nerves. Even more striking were substantial changes in the composition and properties of microtubules in shiverer CNS axons. The density of axonal microtubules is increased, reflecting increased expression of tubulin in shiverer, and the stability of microtubules is drastically reduced in shiverer axons. Shiverer transgenic mice with two copies of a wild-type myelin basic protein transgene have an intermediate level of compact myelin, making it possible to determine whether the actual level of compact myelin is an important regulator of axonal microtubules. Both increased microtubule density and reduced microtubule stability were still observed in transgenic mouse nerves, indicating that signals beyond synaptogenesis and the mere presence of compact myelin are required for normal regulation of the axonal microtubule cytoskeleton.

  11. CNS development: an overview

    Science.gov (United States)

    Nowakowski, R. S.; Hayes, N. L.

    1999-01-01

    The basic principles of the development of the central nervous system (CNS) are reviewed, and their implications for both normal and abnormal development of the brain are discussed. The goals of this review are (a) to provide a set of concepts to aid in understanding the variety of complex processes that occur during CNS development, (b) to illustrate how these concepts contribute to our knowledge of the normal anatomy of the adult brain, and (c) to provide a basis for understanding how modifications of normal developmental processes by traumatic injury, by environmental or experiential influences, or by genetic variations may lead to modifications in the resultant structure and function of the adult CNS.

  12. Drug-induced activation of SREBP-controlled lipogenic gene expression in CNS-related cell lines: Marked differences between various antipsychotic drugs

    Directory of Open Access Journals (Sweden)

    Vik-Mo Audun O

    2006-10-01

    Full Text Available Abstract Background The etiology of schizophrenia is unknown, but neurodevelopmental disturbances, myelin- and oligodendrocyte abnormalities and synaptic dysfunction have been suggested as pathophysiological factors in this severe psychiatric disorder. Cholesterol is an essential component of myelin and has proved important for synapse formation. Recently, we demonstrated that the antipsychotic drugs clozapine and haloperidol stimulate lipogenic gene expression in cultured glioma cells through activation of the sterol regulatory element-binding protein (SREBP transcription factors. We here compare the action of chlorpromazine, haloperidol, clozapine, olanzapine, risperidone and ziprasidone on SREBP activation and SREBP-controlled gene expression (ACAT2, HMGCR, HMGCS1, FDPS, SC5DL, DHCR7, LDLR, FASN and SCD1 in four CNS-relevant human cell lines. Results There were marked differences in the ability of the antipsychotic drugs to activate the expression of SREBP target genes, with clozapine and chlorpromazine as the most potent stimulators in a context of therapeutically relevant concentrations. Glial-like cells (GaMg glioma and CCF-STTG1 astrocytoma cell lines displayed more pronounced drug-induced SREBP activation compared to the response in HCN2 human cortical neurons and SH-SY5Y neuroblastoma cells, indicating that antipsychotic-induced activation of lipogenesis is most prominent in glial cells. Conclusion Our present data show a marked variation in the ability of different antipsychotics to induce SREBP-controlled transcriptional activation of lipogenesis in cultured human CNS-relevant cells. We propose that this effect could be relevant for the therapeutic efficacy of some antipsychotic drugs.

  13. CNS Damage Classification in Newborn Infants by Neural Network Based Cry Analysis

    NARCIS (Netherlands)

    Poel, M.; Ekkel, T.

    2002-01-01

    The central nervous system (CNS) of the human body is the whole system of brain, spinal marrow and nerve cells throughout the body that correlates and regulates the internal reactions of the body and controls its adjustment to the environment. It controls muscles and processes sensory information or

  14. The detection of surfactant proteins A, B, C and D in the human brain and their regulation in cerebral infarction, autoimmune conditions and infections of the CNS.

    Directory of Open Access Journals (Sweden)

    Stefan Schob

    Full Text Available Surfactant proteins (SP have been studied intensively in the respiratory system. Surfactant protein A and surfactant protein D are proteins belonging to the family of collectins each playing a major role in the innate immune system. The ability of surfactant protein A and surfactant protein D to bind various pathogens and facilitate their elimination has been described in a vast number of studies. Surfactant proteins are very important in modulating the host's inflammatory response and participate in the clearance of apoptotic cells. Surfactant protein B and surfactant protein C are proteins responsible for lowering the surface tension in the lungs. The aim of this study was an investigation of expression of surfactant proteins in the central nervous system to assess their specific distribution patterns. The second aim was to quantify surfactant proteins in cerebrospinal fluid of healthy subjects compared to patients suffering from different neuropathologies. The expression of mRNA for the surfactant proteins was analyzed with RT-PCR done with samples from different parts of the human brain. The production of the surfactant proteins in the brain was verified using immunohistochemistry and Western blot. The concentrations of the surfactant proteins in cerebrospinal fluid from healthy subjects and patients suffering from neuropathologic conditions were quantified using ELISA. Our results revealed that surfactant proteins are present in the central nervous system and that the concentrations of one or more surfactant proteins in healthy subjects differed significantly from those of patients affected by central autoimmune processes, CNS infections or cerebral infarction. Based on the localization of the surfactant proteins in the brain, their different levels in normal versus pathologic samples of cerebrospinal fluid and their well-known functions in the lungs, it appears that the surfactant proteins may play roles in host defense of the brain

  15. Indian hedgehog B function is required for the specification of oligodendrocyte progenitor cells in the zebrafish CNS.

    Science.gov (United States)

    Chung, Ah-Young; Kim, Suhyun; Kim, Eunmi; Kim, Dohyun; Jeong, Inyoung; Cha, Young Ryun; Bae, Young-ki; Park, Seung Woo; Lee, Jehee; Park, Hae-Chul

    2013-01-23

    A subset of ventral spinal cord precursors, known as pMN precursor cells, initially generate motor neurons and then oligodendrocyte progenitor cells (OPCs), which migrate and differentiate as myelinating oligodendrocytes in the developing neural tube. The switch between motor neuron and oligodendrocyte production by the pMN neural precursors is an important step in building a functional nervous system. However, the precise mechanism that orchestrates the sequential generation of motor neurons and oligodendrocytes within the common population of pMN precursors is still unclear. The current study demonstrates that Indian Hedgehog b (Ihhb), previously known as Echidna Hedgehog, begins to be expressed in the floor plate cells of the ventral spinal cord at the time of OPC specification in zebrafish embryos. Ihhb loss-of-function analysis revealed that Ihhb function is required for OPC specification from pMN precursors by negatively regulating the proliferation of neural precursors. Finally, results showed that Sonic Hedgehog (Shh) could not replace Ihhb function in OPC specification, suggesting that Ihhb and Shh play separate roles in OPC specification. Altogether, data from the present study suggested a novel mechanism, mediated by Ihhb, for the sequential generation of motor neurons and oligodendrocytes from pMN precursors in the ventral spinal cord of zebrafish embryos.

  16. Chemokines in the balance: maintenance of homeostasis and protection at CNS barriers

    Directory of Open Access Journals (Sweden)

    Jessica L Williams

    2014-05-01

    Full Text Available In the adult central nervous system (CNS, chemokines and their receptors are involved in developmental, physiological and pathological processes. Although most lines of investigation focus on their ability to induce the migration of cells, recent studies indicate that chemokines also promote cellular interactions and activate signaling pathways that maintain CNS homeostatic functions. Many homeostatic chemokines are expressed on the vasculature of the blood brain barrier including CXCL12, CCL19, CCL20, and CCL21. While endothelial cell expression of these chemokines is known to regulate the entry of leukocytes into the CNS during immunosurveillance, new data indicate that CXCL12 is also involved in diverse cellular activities including adult neurogenesis and neuronal survival, having an opposing role to the homeostatic chemokine, CXCL14, which appears to regulate synaptic inputs to neural precursors. Neuronal expression of CX3CL1, yet another homeostatic chemokine that promotes neuronal survival and communication with microglia, is partly regulated by CXCL12. Regulation of CXCL12 is unique in that it may regulate its own expression levels via binding to its scavenger receptor CXCR7/ACKR3. In this review, we explore the diverse roles of these and other homeostatic chemokines expressed within the CNS, including the possible implications of their dysfunction as a cause of neurologic disease.

  17. Meningitis Caused by Toscana Virus Is Associated with Strong Antiviral Response in the CNS and Altered Frequency of Blood Antigen-Presenting Cells

    Directory of Open Access Journals (Sweden)

    Stefania Varani

    2015-11-01

    Full Text Available Toscana virus (TOSV is a Phlebotomus-transmitted RNA virus and a frequent cause of human meningitis and meningoencephalitis in Southern Europe during the summer season. While evidence for TOSV-related central nervous system (CNS cases is increasing, little is known about the host defenses against TOSV. We evaluated innate immune response to TOSV by analyzing frequency and activation of blood antigen-presenting cells (APCs and cytokine levels in plasma and cerebrospinal fluid (CSF from patients with TOSV neuroinvasive infection and controls. An altered frequency of different blood APC subsets was observed in TOSV-infected patients, with signs of monocytic deactivation. Nevertheless, a proper or even increased responsiveness of toll-like receptor 3 and 7/8 was observed in blood APCs of these patients as compared to healthy controls. Systemic levels of cytokines remained low in TOSV-infected patients, while levels of anti-inflammatory and antiviral mediators were significantly higher in CSF from TOSV-infected patients as compared to patients with other infectious and noninfectious neurological diseases. Thus, the early host response to TOSV appears effective for viral clearance, by proper response to TLR3 and TLR7/8 agonists in peripheral blood and by a strong and selective antiviral and anti-inflammatory response in the CNS.

  18. Cell swelling and volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay

    1992-01-01

    The extracellular space in the brain is typically 20% of the tissue volume and is reduced to at least half its size under conditions of neural insult. Whether there is a minimum size to the extracellular space was discussed. A general model for cell volume regulation was presented, followed...... by a discussion on how many of the generally involved mechanisms are identified in neural cells and (or) in astrocytes. There seems to be clear evidence suggesting that parallel K+ and Cl- channels mediate regulatory volume decrease in primary cultures of astrocytes, and a stretch-activated cation channel has...

  19. Targeting gene therapy vectors to CNS malignancies.

    Science.gov (United States)

    Spear, M A; Herrlinger, U; Rainov, N; Pechan, P; Weissleder, R; Breakefield, X O

    1998-04-01

    Gene therapy offers significant advantages to the field of oncology with the addition of specifically and uniquely engineered mechanisms of halting malignant proliferation through cytotoxicity or reproductive arrest. To confer a true benefit to the therapeutic ratio (the relative toxicity to tumor compared to normal tissue) a vector or the transgene it carries must selectively affect or access tumor cells. Beyond the selective toxicities of many transgene products, which frequently parallel that of contemporary chemotherapeutic agents, lies the potential utility of targeting the vector. This review presents an overview of current and potential methods for designing vectors targeted to CNS malignancies through selective delivery, cell entry, transport or transcriptional regulation. The topic of delivery encompasses physical and pharmaceutic means of increasing the relative exposure of tumors to vector. Cell entry based methodologies are founded on increasing relative uptake of vector through the chemical or recombinant addition of ligand and antibody domains which selectively bind receptors expressed on target cells. Targeted transport involves the potential for using cells to selectively carry vectors or transgenes into tumors. Finally, promoter and enhancer systems are discussed which have potential for selectivity activating transcription to produce targeted transgene expression or vector propagation. PMID:9584951

  20. Targeted Intra-arterial Transplantation of Stem Cells to the Injured CNS is More Effective than Intravenous Administration - Engraftment is Dependent on Cell Type and Adhesion Molecule Expression

    DEFF Research Database (Denmark)

    Lundberg, Johan; Södersten, Erik; Sundström, Erik;

    2011-01-01

    with inflammation, such as traumatic brain injury, there is a transient up-regulation of ICAM-1 and VCAM-1 which might provide enviromental cues for migration of stem cells from blood to parenchyma. The aim of this study was to i) analyze the effect of intra-arterial administration on cellular engraftment, ii...

  1. Ion Channels Involved in Cell Volume Regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay

    2011-01-01

    regulatory ion channels involved, and the mechanisms (cellular signalling pathways) that regulate these channels. Finally, I shall also briefly review current investigations in these two cell lines that focuses on how changes in cell volume can regulate cell functions such as cell migration, proliferation...

  2. Melphalan, Carboplatin, Mannitol, and Sodium Thiosulfate in Treating Patients With Recurrent or Progressive CNS Embryonal or Germ Cell Tumors

    Science.gov (United States)

    2016-04-28

    Adult Central Nervous System Germ Cell Tumor; Adult Ependymoblastoma; Adult Medulloblastoma; Adult Pineoblastoma; Adult Supratentorial Primitive Neuroectodermal Tumor; Childhood Atypical Teratoid/Rhabdoid Tumor; Childhood Central Nervous System Germ Cell Tumor; Childhood Ependymoblastoma; Medulloepithelioma; Ototoxicity; Recurrent Adult Brain Neoplasm; Recurrent Childhood Central Nervous System Embryonal Neoplasm; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor

  3. CNS Diseases and Uveitis

    OpenAIRE

    Pia Allegri; Roberto Rissotto; Herbort, Carl P.; Ugo Murialdo

    2011-01-01

    A number of inflammatory, infectious, neoplastic and idiopathic disorders affect the eye and the central nervous system (CNS) concurrently or at different time frames. These conditions pose a diagnostic challenge to the clinician since they may present with similar ocular and neurological manifestations. The purpose of this review is to describe major neurological syndromes including multiple sclerosis, Vogt-Koyanagi- Harada disease, other autoimmune syndromes, and several infectious diseases...

  4. Early treatment with anti-VLA-4 mAb can prevent the infiltration and/or development of pathogenic CD11b+CD4+ T cells in the CNS during progressive EAE.

    Directory of Open Access Journals (Sweden)

    John E Mindur

    Full Text Available Natalizumab is a humanized monoclonal antibody against the leukocyte adhesion molecule very late antigen (VLA-4, and is currently an approved therapy for patients with relapsing-remitting multiple sclerosis (RRMS. However, it is unknown whether natalizumab is beneficial for progressive forms of MS. Therefore, we assessed the effects of anti-VLA-4 monoclonal antibody (mAb therapy in a progressive experimental autoimmune encephalomyelitis (EAE mouse model. Notably, we found that early therapy could significantly reduce the severity of progressive EAE, while treatment initiated at an advanced stage was less efficient. Furthermore, we observed the accumulation of a novel subset of GM-CSF-producing CD11b+CD4+ T cells in the CNS throughout disease progression. Importantly, early therapeutic anti-VLA-4 mAb treatment suppressed the accumulation of these GM-CSF-producing CD11b+CD4+ T cells in the CNS along with activated microglia/macrophages populations, and also conferred a protective effect against inflammation-mediated neurodegeneration, including demyelination and axonal loss. Collectively, our data suggest that early treatment with anti-VLA-4 mAb can provide neuroprotection against progressive CNS autoimmune disease by preventing the accumulation of pathogenic GM-CSF-producing CD11b+CD4+ T cells in the CNS.

  5. Role of CXCR4-mediated bone marrow colonization in CNS infiltration by T cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Jost, Tanja Rezzonico; Borga, Chiara; Radaelli, Enrico; Romagnani, Andrea; Perruzza, Lisa; Omodho, Lorna; Cazzaniga, Giovanni; Biondi, Andrea; Indraccolo, Stefano; Thelen, Marcus; Te Kronnie, Geertruy; Grassi, Fabio

    2016-06-01

    Infiltration of the central nervous system is a severe trait of T cell acute lymphoblastic leukemia. Inhibition of CXC chemokine receptor 4 significantly ameliorates T cell acute lymphoblastic leukemia in murine models of the disease; however, signaling by CXC chemokine receptor 4 is important in limiting the divagation of peripheral blood mononuclear cells out of the perivascular space into the central nervous system parenchyma. Therefore, Inhibition of CXC chemokine receptor 4 potentially may untangle T cell acute lymphoblastic leukemia cells from retention outside the brain. Here, we show that leukemic lymphoblasts massively infiltrate cranial bone marrow, with diffusion to the meninges without invasion of the brain parenchyma, in mice that underwent xenotransplantation with human T cell acute lymphoblastic leukemia cells or that developed leukemia from transformed hematopoietic progenitors. We tested the hypothesis that T cell acute lymphoblastic leukemia neuropathology results from meningeal infiltration through CXC chemokine receptor 4-mediated bone marrow colonization. Inhibition of leukemia engraftment in the bone marrow by pharmacologic CXC chemokine receptor 4 antagonism significantly ameliorated neuropathologic aspects of the disease. Genetic deletion of CXCR4 in murine hematopoietic progenitors abrogated leukemogenesis induced by constitutively active Notch1, whereas lack of CCR6 and CCR7, which have been shown to be involved in T cell and leukemia extravasation into the central nervous system, respectively, did not influence T cell acute lymphoblastic leukemia development. We hypothesize that lymphoblastic meningeal infiltration as a result of bone marrow colonization is responsible for the degenerative alterations of the neuroparenchyma as well as the alteration of cerebrospinal fluid drainage in T cell acute lymphoblastic leukemia xenografts. Therefore, CXC chemokine receptor 4 may constitute a pharmacologic target for T cell acute lymphoblastic

  6. Low Density Lipoprotein Receptor Related Proteins as Regulators of Neural Stem and Progenitor Cell Function

    Directory of Open Access Journals (Sweden)

    Loic Auderset

    2016-01-01

    Full Text Available The central nervous system (CNS is a highly organised structure. Many signalling systems work in concert to ensure that neural stem cells are appropriately directed to generate progenitor cells, which in turn mature into functional cell types including projection neurons, interneurons, astrocytes, and oligodendrocytes. Herein we explore the role of the low density lipoprotein (LDL receptor family, in particular family members LRP1 and LRP2, in regulating the behaviour of neural stem and progenitor cells during development and adulthood. The ability of LRP1 and LRP2 to bind a diverse and extensive range of ligands, regulate ligand endocytosis, recruit nonreceptor tyrosine kinases for direct signal transduction and signal in conjunction with other receptors, enables them to modulate many crucial neural cell functions.

  7. Leptomeningeal metastasis of primary central nervous system (CNS) neoplasms.

    Science.gov (United States)

    Engelhard, Herbert H; Corsten, Luke A

    2005-01-01

    Leptomeningeal dissemination of primary CNS tumors varies widely by histologic subtype. In certain tumors including medulloblastoma, ependymoma, germ cell tumors, and primary CNS lymphoma, seeding of the cerebrospinal fluid space is a critical factor in determining stage, prognosis and appropriate therapy. Other tumor types, such as glioma, may have radiographic evidence of leptomeningeal metastases without clear impact on prognosis or therapy. PMID:16211884

  8. In situ expansion of T cells that recognize distinct self-antigens sustains autoimmunity in the CNS.

    Science.gov (United States)

    Ramadan, Abdulraouf; Lucca, Liliana E; Carrié, Nadège; Desbois, Sabine; Axisa, Pierre-Paul; Hayder, Myriam; Bauer, Jan; Liblau, Roland S; Mars, Lennart T

    2016-05-01

    Polyspecific T cells recognizing multiple distinct self-antigens have been identified in multiple sclerosis and other organ-specific autoimmune diseases, but their pathophysiological relevance remains undetermined. Using a mouse model of multiple sclerosis, we show that autoimmune encephalomyelitis induction is strictly dependent on reactivation of pathogenic T cells by a peptide (35-55) derived from myelin oligodendrocyte glycoprotein (MOG). This disease-inducing response wanes after onset. Strikingly, the progression of disease is driven by the in situ activation and expansion of a minority of MOG35-55-specific T cells that also recognize neurofilament-medium (NF-M)15-35, an intermediate filament protein expressed in neurons. This mobilization of bispecific T cells is critical for disease progression as adoptive transfer of NF-M15-35/MOG35-55 bispecific T cell lines caused full-blown disease in wild-type but not NF-M-deficient recipients. Moreover, specific tolerance through injection of NF-M15-35 peptide at the peak of disease halted experimental autoimmune encephalomyelitis progression. Our findings highlight the importance of polyspecific autoreactive T cells in the aggravation and perpetuation of central nervous system autoimmunity. PMID:27000832

  9. Myeloid cell transmigration across the CNS vasculature triggers IL-1β-driven neuroinflammation during autoimmune encephalomyelitis in mice.

    Science.gov (United States)

    Lévesque, Sébastien A; Paré, Alexandre; Mailhot, Benoit; Bellver-Landete, Victor; Kébir, Hania; Lécuyer, Marc-André; Alvarez, Jorge Ivan; Prat, Alexandre; de Rivero Vaccari, Juan Pablo; Keane, Robert W; Lacroix, Steve

    2016-05-30

    Growing evidence supports a role for IL-1 in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE), but how it impacts neuroinflammation is poorly understood. We show that susceptibility to EAE requires activation of IL-1R1 on radiation-resistant cells via IL-1β secreted by bone marrow-derived cells. Neutrophils and monocyte-derived macrophages (MDMs) are the main source of IL-1β and produce this cytokine as a result of their transmigration across the inflamed blood-spinal cord barrier. IL-1R1 expression in the spinal cord is found in endothelial cells (ECs) of the pial venous plexus. Accordingly, leukocyte infiltration at EAE onset is restricted to IL-1R1(+) subpial and subarachnoid vessels. In response to IL-1β, primary cultures of central nervous system ECs produce GM-CSF, G-CSF, IL-6, Cxcl1, and Cxcl2. Initiation of EAE or subdural injection of IL-1β induces a similar cytokine/chemokine signature in spinal cord vessels. Furthermore, the transfer of Gr1(+) cells on the spinal cord is sufficient to induce illness in EAE-resistant IL-1β knockout (KO) mice. Notably, transfer of Gr1(+) cells isolated from C57BL/6 mice induce massive recruitment of recipient myeloid cells compared with cells from IL-1β KO donors, and this recruitment translates into more severe paralysis. These findings suggest that an IL-1β-dependent paracrine loop between infiltrated neutrophils/MDMs and ECs drives neuroinflammation. PMID:27139491

  10. CNS Diseases and Uveitis

    Directory of Open Access Journals (Sweden)

    Pia Allegri

    2011-01-01

    Full Text Available A number of inflammatory, infectious, neoplastic and idiopathic disorders affect the eye and the central nervous system (CNS concurrently or at different time frames. These conditions pose a diagnostic challenge to the clinician since they may present with similar ocular and neurological manifestations. The purpose of this review is to describe major neurological syndromes including multiple sclerosis, Vogt-Koyanagi- Harada disease, other autoimmune syndromes, and several infectious diseases which may affect the eye. This article may serve as a guide for the diagnosis and treatment of such disorders. It should be noted that these conditions have been viewed from a neurologist′s perspective thereby neurologic involvement is stressed.

  11. CNS diseases and uveitis.

    Science.gov (United States)

    Allegri, Pia; Rissotto, Roberto; Herbort, Carl P; Murialdo, Ugo

    2011-10-01

    A number of inflammatory, infectious, neoplastic and idiopathic disorders affect the eye and the central nervous system (CNS) concurrently or at different time frames. These conditions pose a diagnostic challenge to the clinician since they may present with similar ocular and neurological manifestations. The purpose of this review is to describe major neurological syndromes including multiple sclerosis, Vogt-Koyanagi-Harada disease, other autoimmune syndromes, and several infectious diseases which may affect the eye. This article may serve as a guide for the diagnosis and treatment of such disorders. It should be noted that these conditions have been viewed from a neurologist's perspective thereby neurologic involvement is stressed. PMID:22454751

  12. Cell cycle regulation in Trypanosoma brucei

    OpenAIRE

    Tansy C Hammarton

    2007-01-01

    Cell division is regulated by intricate and interconnected signal transduction pathways that precisely coordinate, in time and space, the complex series of events involved in replicating and segregating the component parts of the cell. In Trypanosoma brucei, considerable progress has been made over recent years in identifying molecular regulators of the cell cycle and elucidating their functions, although many regulators undoubtedly remain to be identified, and there is still a long way to go...

  13. Preserved vascular integrity and enhanced survival following neuropilin-1 inhibition in a mouse model of CD8 T cell-initiated CNS vascular permeability

    Directory of Open Access Journals (Sweden)

    Suidan Georgette L

    2012-09-01

    Full Text Available Abstract Background Altered permeability of the blood–brain barrier (BBB is a feature of numerous neurological conditions including multiple sclerosis, cerebral malaria, viral hemorrhagic fevers and acute hemorrhagic leukoencephalitis. Our laboratory has developed a murine model of CD8 T cell-initiated central nervous system (CNS vascular permeability in which vascular endothelial growth factor (VEGF signaling plays a prominent role in BBB disruption. Findings In this study, we addressed the hypothesis that in vivo blockade of VEGF signal transduction through administration of peptide (ATWLPPR to inhibit neuropilin-1 (NRP-1 would have a therapeutic effect following induction of CD8 T cell-initiated BBB disruption. We report that inhibition of NRP-1, a co-receptor that enhances VEGFR2 (flk-1 receptor activation, decreases vascular permeability, brain hemorrhage, and mortality in this model of CD8 T cell-initiated BBB disruption. We also examine the expression pattern of VEGFR2 (flk-1 and VEGFR1 (flt-1 mRNA expression during a time course of this condition. We find that viral infection of the brain leads to increased expression of flk-1 mRNA. In addition, flk-1 and flt-1 expression levels decrease in the striatum and hippocampus in later time points following induction of CD8 T cell-mediated BBB disruption. Conclusion This study demonstrates that NRP-1 is a potential therapeutic target in neuro-inflammatory diseases involving BBB disruption and brain hemorrhage. Additionally, the reduction in VEGF receptors subsequent to BBB disruption could be involved in compensatory negative feedback as an attempt to reduce vascular permeability.

  14. Bone Morphogenetic Protein 4 Signalling in Neural Stem and Progenitor Cells during Development and after Injury

    Directory of Open Access Journals (Sweden)

    Alistair E. Cole

    2016-01-01

    Full Text Available Substantial progress has been made in identifying the extracellular signalling pathways that regulate neural stem and precursor cell biology in the central nervous system (CNS. The bone morphogenetic proteins (BMPs, in particular BMP4, are key players regulating neuronal and glial cell development from neural precursor cells in the embryonic, postnatal, and injured CNS. Here we review recent studies on BMP4 signalling in the generation of neurons, astrocytes, and oligodendroglial cells in the CNS. We also discuss putative mechanisms that BMP4 may utilise to influence glial cell development following CNS injury and highlight some questions for further research.

  15. Lipid oxidation and peroxidation in CNS health and disease: from molecular mechanisms to therapeutic opportunities.

    Science.gov (United States)

    Adibhatla, Rao Muralikrishna; Hatcher, James Franklin

    2010-01-01

    Reactive oxygen species (ROS) are produced at low levels in mammalian cells by various metabolic processes, such as oxidative phosphorylation by the mitochondrial respiratory chain, NAD(P)H oxidases, and arachidonic acid oxidative metabolism. To maintain physiological redox balance, cells have endogenous antioxidant defenses regulated at the transcriptional level by Nrf2/ARE. Oxidative stress results when ROS production exceeds the cell's ability to detoxify ROS. Overproduction of ROS damages cellular components, including lipids, leading to decline in physiological function and cell death. Reaction of ROS with lipids produces oxidized phospholipids, which give rise to 4-hydroxynonenal, 4-oxo-2-nonenal, and acrolein. The brain is susceptible to oxidative damage due to its high lipid content and oxygen consumption. Neurodegenerative diseases (AD, ALS, bipolar disorder, epilepsy, Friedreich's ataxia, HD, MS, NBIA, NPC, PD, peroxisomal disorders, schizophrenia, Wallerian degeneration, Zellweger syndrome) and CNS traumas (stroke, TBI, SCI) are problems of vast clinical importance. Free iron can react with H(2)O(2) via the Fenton reaction, a primary cause of lipid peroxidation, and may be of particular importance for these CNS injuries and disorders. Cholesterol is an important regulator of lipid organization and the precursor for neurosteroid biosynthesis. Atherosclerosis, the major risk factor for ischemic stroke, involves accumulation of oxidized LDL in the arteries, leading to foam cell formation and plaque development. This review will discuss the role of lipid oxidation/peroxidation in various CNS injuries/disorders. PMID:19624272

  16. Materials as stem cell regulators

    Science.gov (United States)

    Murphy, William L.; McDevitt, Todd C.; Engler, Adam J.

    2014-06-01

    The stem cell/material interface is a complex, dynamic microenvironment in which the cell and the material cooperatively dictate one another's fate: the cell by remodelling its surroundings, and the material through its inherent properties (such as adhesivity, stiffness, nanostructure or degradability). Stem cells in contact with materials are able to sense their properties, integrate cues via signal propagation and ultimately translate parallel signalling information into cell fate decisions. However, discovering the mechanisms by which stem cells respond to inherent material characteristics is challenging because of the highly complex, multicomponent signalling milieu present in the stem cell environment. In this Review, we discuss recent evidence that shows that inherent material properties may be engineered to dictate stem cell fate decisions, and overview a subset of the operative signal transduction mechanisms that have begun to emerge. Further developments in stem cell engineering and mechanotransduction are poised to have substantial implications for stem cell biology and regenerative medicine.

  17. IL-21 optimizes T cell and humoral responses in the central nervous system during viral encephalitis

    Science.gov (United States)

    Phares, Timothy W.; DiSano, Krista D.; Hinton, David R.; Hwang, Mihyun; Zajac, Allan J.; Stohlman, Stephen A.; Bergmann, Cornelia C.

    2013-01-01

    Acute coronavirus encephalomyelitis is controlled by T cells while humoral responses suppress virus persistence. This study defines the contribution of interleukin (IL)-21, a regulator of T and B cell function, to central nervous system (CNS) immunity. IL-21 receptor deficiency did not affect peripheral T cell activation or trafficking, but dampened granzyme B, gamma interferon and IL-10 expression by CNS T cells and reduced serum and intrathecal humoral responses. Viral control was already lost prior to humoral CNS responses, but demyelination remained comparable. These data demonstrate a critical role of IL-21 in regulating CNS immunity, sustaining viral persistence and preventing mortality. PMID:23992866

  18. Regulating cell differentiation at different layers

    Institute of Scientific and Technical Information of China (English)

    Jiarui Wu

    2011-01-01

    Cell differentiation is a basic behavior in the developmental process of multi-cellular organisms,through which various cell types are generated from one embryonic cell for further building different tissues and organs of animals or plants.It is estimated that there are more than two hundred cell types in a human body.To understand the molecular mechanisms of cell differentiation,researchers usually focus on a question how particular genes are selectively expressed during the differentiation process.However,more and more evidence indicates that the regulation of cell differentiation is far beyond simply controlling the expression of genetic program,which is supported by the collection of four research articles in this issue that the regulation of cell differentiation involves various factors at different layers,including epigenetics,metabolism and cell-cell interaction.

  19. Metformin ameliorates the development of experimental autoimmune encephalomyelitis by regulating T helper 17 and regulatory T cells in mice.

    Science.gov (United States)

    Sun, Yafei; Tian, Tian; Gao, Juan; Liu, Xiaoqian; Hou, Huiqing; Cao, Runjing; Li, Bin; Quan, Moyuan; Guo, Li

    2016-03-15

    Immoderate immunoreaction of antigen-specific Th17 and Treg cell dysfunction play critical roles in the pathogenesis of multiple sclerosis. We examined Th17/Treg immune responses and the underlying mechanisms in response to metformin in C57BL/6 mice with experimental autoimmune encephalomyelitis (EAE). Metformin reduced Th17 and increased Treg cell percentages along with the levels of associated cytokines. Molecules involved in cellular metabolism were altered in mice with EAE. Suppressed activation of mTOR and its downstream target, HIF-1α, likely mediated the protective effects of metformin. Our findings demonstrate that regulation of T cell metabolism represents a new therapeutic target for CNS autoimmune disorders.

  20. Prominent Vascular and Perivascular Eosinophilic Infiltrates Heralding CNS Mycosis Fungoides.

    Science.gov (United States)

    Schowinsky, Jeffrey; Leppert, Michelle; Ney, Douglas; Kleinschmidt-DeMasters, B K

    2015-10-01

    Brain parenchymal involvement of mycosis fungoides (MF) is very rare. This study reports a patient with known cutaneous MF (under treatment) who presented with a CNS syndrome and multiple brain lesions. Brain biopsy demonstrated massive eosinophilic infiltrates but no MF cells. Despite treatment, new lesions developed and the patient died. At autopsy, there was massive involvement MF cells, suggesting that the eosinophilic infiltrates presaged the severe involvement of the CNS by MF. PMID:26352990

  1. Regulating the leukemia stem cell

    OpenAIRE

    Cleary, Michael L.

    2009-01-01

    Leukemia stem cells (LSCs) are responsible for sustaining and propagating malignant disease, and, as such, are promising targets for therapy. Studies of human LSCs have served an important role in defining the major tenets of the cancer stem cell model, which center on the frequencies of cancer stem cells, their potential hierarchical organization, and their degree of maturation. LSCs in acute myeloid leukemia (AML) have recently been studied using mouse syngeneic models of leukemia induced b...

  2. RETINOIDS REGULATE STEM CELL DIFFERENTIATION

    OpenAIRE

    Gudas, Lorraine J.; Wagner, John A.

    2011-01-01

    Retinoids are ubiquitous signaling molecules that influence nearly every cell type, exert profound effects on development, and complement cancer chemotherapeutic regimens. All-trans retinoic acid (RA) and other active retinoids are generated from vitamin A (retinol), but key aspects of the signaling pathways required to produce active retinoids remain unclear. Retinoids generated by one cell type can affect nearby cells, so retinoids also function in intercellular communication. RA induces di...

  3. Regulation of Power Conversion in Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    SHEN Mu-zhong; ZHANG J.; K. Scott

    2004-01-01

    Here we report a regulation about power conversion in fuel cells. This regulation is expressed as that total power produced by fuel cells is always proportional to the square of the potential difference between the equilibrium potential and work potential. With this regulation we deduced fuel cell performance equation which can describe the potential vs. the current performance curves, namely, polarization curves of fuel cells with three power source parameters: equilibrium potential E0; internal resistance R; and power conversion coefficient K. The concept of the power conversion coefficient is a new criterion to evaluate and compare the characteristics and capacity of different fuel cells. The calculated values obtained with this equation agree with practical performance of different types of fuel cells.

  4. Flavonoids and the CNS

    Directory of Open Access Journals (Sweden)

    Anna K. Jäger

    2011-02-01

    Full Text Available Flavonoids are present in almost all terrestrial plants, where they provide UV-protection and colour. Flavonoids have a fused ring system consisting of an aromatic ring and a benzopyran ring with a phenyl substituent. The flavonoids can be divided into several classes depending on their structure. Flavonoids are present in food and medicinal plants and are thus consumed by humans. They are found in plants as glycosides. Before oral absorption, flavonoids undergo deglycosylation either by lactase phloridzin hydrolase or cytosolic β-glucocidase. The absorbed aglycone is then conjugated by methylation, sulphatation or glucuronidation. Both the aglycones and the conjugates can pass the blood-brain barrier. In the CNS several flavones bind to the benzodiazepine site on the GABAA-receptor resulting in sedation, anxiolytic or anti-convulsive effects. Flavonoids of several classes are inhibitors of monoamine oxidase A or B, thereby working as anti-depressants or to improve the conditions of Parkinson’s patients. Flavanols, flavanones and anthocyanidins have protective effects preventing inflammatory processes leading to nerve injury. Flavonoids seem capable of influencing health and mood.

  5. Potential for Cell-Transplant Therapy with Human Neuronal Precursors to Treat Neuropathic Pain in Models of PNS and CNS Injury: Comparison of hNT2.17 and hNT2.19 Cell Lines

    Directory of Open Access Journals (Sweden)

    Mary J. Eaton

    2012-01-01

    Full Text Available Effective treatment of sensory neuropathies in peripheral neuropathies and spinal cord injury (SCI is one of the most difficult problems in modern clinical practice. Cell therapy to release antinociceptive agents near the injured spinal cord is a logical next step in the development of treatment modalities. But few clinical trials, especially for chronic pain, have tested the potential of transplant of cells to treat chronic pain. Cell lines derived from the human neuronal NT2 cell line parentage, the hNT2.17 and hNT2.19 lines, which synthesize and release the neurotransmitters gamma-aminobutyric acid (GABA and serotonin (5HT, respectively, have been used to evaluate the potential of cell-based release of antinociceptive agents near the lumbar dorsal (horn spinal sensory cell centers to relieve neuropathic pain after PNS (partial nerve and diabetes-related injury and CNS (spinal cord injury damage in rat models. Both cell lines transplants potently and permanently reverse behavioral hypersensitivity without inducing tumors or other complications after grafting. Functioning as cellular minipumps for antinociception, human neuronal precursors, like these NT2-derived cell lines, would likely provide a useful adjuvant or replacement for current pharmacological treatments for neuropathic pain.

  6. Mockup tests for developing the CARR-CNS with a two-phase thermo-siphon loop

    Institute of Scientific and Technical Information of China (English)

    DU She-Jiao; BI Qin-Cheng; CHEN Ting-Kuan; FENG Quan-Ke; LI Xiao-Ming

    2004-01-01

    The cold neutron source (CNS) is a facility to increase cold neutrons by scattering thermal neutrons in liquid hydrogen or deuterium around 20 K. For extracting a stable cold neutron flux fiom the CNS, the liquid quantity in the moderator cell should be maintained stably against disturbance of nuclear heating. The China Institute of Atomic Energy (CIAE) is now constructing the China Advanced Research Reactor (CARR: 60 MW), and designing the CARR-CNS with a two-phase thermo-siphon loop consisting of a condenser, two moderator transfer tubes and an annular cylindrical moderator cell. The mock-up tests were carried out using a full-scale loop with Freon-113, for validating the self-regulating characteristics of the loop, the void fraction less than 20% in the liquid hydrogen of the moderator cell, and the requirements for establishing the condition under which the inner shell has only vapor. The density ratio of liquid to vapor and the volumetric evaporation rate due to heat load are kept the same as those in normal operation of the CARR-CNS. The results show that the loop has the self-regulating characteristics and the inner shell contains only vapor, while the outer shell liquid. The local void fraction in the liquid increases with increasing of the loop pressure.

  7. Cell Size Regulation in Bacteria

    Science.gov (United States)

    Amir, Ariel

    2014-05-01

    Various bacteria such as the canonical gram negative Escherichia coli or the well-studied gram positive Bacillus subtilis divide symmetrically after they approximately double their volume. Their size at division is not constant, but is typically distributed over a narrow range. Here, we propose an analytically tractable model for cell size control, and calculate the cell size and interdivision time distributions, as well as the correlations between these variables. We suggest ways of extracting the model parameters from experimental data, and show that existing data for E. coli supports partial size control, and a particular explanation: a cell attempts to add a constant volume from the time of initiation of DNA replication to the next initiation event. This hypothesis accounts for the experimentally observed correlations between mother and daughter cells as well as the exponential dependence of size on growth rate.

  8. Alcohol intake alters immune responses and promotes CNS viral persistence in mice.

    Science.gov (United States)

    Loftis, Jennifer M; Taylor, Jonathan; Raué, Hans-Peter; Slifka, Mark K; Huang, Elaine

    2016-10-01

    Chronic hepatitis C virus (HCV) infection leads to progressive liver disease and is associated with a variety of extrahepatic effects, including central nervous system (CNS) damage and neuropsychiatric impairments. Alcohol abuse can exacerbate these adverse effects on brain and behavior, but the molecular mechanisms are not well understood. This study investigated the role of alcohol in regulating viral persistence and CNS immunopathology in mice infected with lymphocytic choriomeningitis virus (LCMV), a model for HCV infections in humans. Female and male BALB/c mice (n=94) were exposed to alcohol (ethanol; EtOH) and water (or water only) using a two-bottle choice paradigm, followed one week later by infection with either LCMV clone 13 (causes chronic infection similar to chronic HCV), LCMV Armstrong (causes acute infection), or vehicle. Mice were monitored for 60days post-infection and continued to receive 24-h access to EtOH and water. Animals infected with LCMV clone 13 drank more EtOH, as compared to those with an acute or no viral infection. Six weeks after infection with LCMV clone 13, mice with EtOH exposure evidenced higher serum viral titers, as compared to mice without EtOH exposure. EtOH intake was also associated with reductions in virus-specific CD8(+) T cell frequencies (particularly CD11a(hi) subsets) and evidence of persistent CNS viremia in chronically infected mice. These findings support the hypothesis that EtOH use and chronic viral infection can result in combined toxic effects accelerating CNS damage and neuropsychiatric dysfunction and suggest that examining the role of EtOH in regulating viral persistence and CNS immunopathology in mice infected with LCMV can lead to a more comprehensive understanding of comorbid alcohol use disorder and chronic viral infection. PMID:27269869

  9. Biophysical regulation of stem cell differentiation.

    Science.gov (United States)

    Govey, Peter M; Loiselle, Alayna E; Donahue, Henry J

    2013-06-01

    Bone adaptation to its mechanical environment, from embryonic through adult life, is thought to be the product of increased osteoblastic differentiation from mesenchymal stem cells. In parallel with tissue-scale loading, these heterogeneous populations of multipotent stem cells are subject to a variety of biophysical cues within their native microenvironments. Bone marrow-derived mesenchymal stem cells-the most broadly studied source of osteoblastic progenitors-undergo osteoblastic differentiation in vitro in response to biophysical signals, including hydrostatic pressure, fluid flow and accompanying shear stress, substrate strain and stiffness, substrate topography, and electromagnetic fields. Furthermore, stem cells may be subject to indirect regulation by mechano-sensing osteocytes positioned to more readily detect these same loading-induced signals within the bone matrix. Such paracrine and juxtacrine regulation of differentiation by osteocytes occurs in vitro. Further studies are needed to confirm both direct and indirect mechanisms of biophysical regulation within the in vivo stem cell niche.

  10. Cell volume regulation: physiology and pathophysiology

    DEFF Research Database (Denmark)

    Lambert, I H; Hoffmann, E K; Pedersen, Stine Helene Falsig

    2008-01-01

    Cell volume perturbation initiates a wide array of intracellular signalling cascades, leading to protective and adaptive events and, in most cases, activation of volume-regulatory osmolyte transport, water loss, and hence restoration of cell volume and cellular function. Cell volume is challenged....../hypernatremia. On the other hand, it has recently become clear that an increase or reduction in cell volume can also serve as a specific signal in the regulation of physiological processes such as transepithelial transport, cell migration, proliferation and death. Although the mechanisms by which cell volume perturbations...

  11. CNS Vasculitis Associated with Waldenström Macroglobulinemia

    Science.gov (United States)

    Riangwiwat, Tanawan; Wu, Chris Y.; Santos-Ocampo, Alberto S.; Liu, Randal J.

    2016-01-01

    Waldenström macroglobulinemia (WM) is an indolent B cell lymphoproliferative disorder with monoclonal IgM secretion. We present a patient with WM who presented with multifocal acute cortical ischemic strokes and was found to have central nervous system (CNS) vasculitis. Workup was negative for cryoglobulins and hyperviscosity syndrome. Immunosuppression with intravenous steroids and cyclophosphamide stabilized the patient's mental status and neurologic deficits. On followup over 7 years, patient gained independence from walking aids and experienced no recurrences of CNS vasculitis. To our knowledge, CNS vasculitis in a WM patient, in the absence of cryoglobulins, has not been reported. Immunosuppression is the preferred treatment.

  12. Recognition and Regulation of T Cells by NK Cells

    Science.gov (United States)

    Pallmer, Katharina; Oxenius, Annette

    2016-01-01

    Regulation of T cell responses by innate lymphoid cells (ILCs) is increasingly documented and studied. Direct or indirect crosstalk between ILCs and T cells early during and after T cell activation can affect their differentiation, polarization, and survival. Natural killer (NK) cells that belong to the ILC1 group were initially described for their function in recognizing and eliminating “altered self” and as source of early inflammatory cytokines, most notably type II interferon. Using signals conveyed by various germ-line encoded activating and inhibitory receptors, NK cells are geared to sense sudden cellular changes that can be caused by infection events, malignant transformation, or cellular stress responses. T cells, when activated by TCR engagement (signal 1), costimulation (signal 2), and cytokines (signal 3), commit to a number of cellular alterations, including entry into rapid cell cycling, metabolic changes, and acquisition of effector functions. These abrupt changes may alert NK cells, and T cells might thereby expose themselves as NK cell targets. Here, we review how activated T cells can be recognized and regulated by NK cells and what consequences such regulation bears for T cell immunity in the context of vaccination, infection, or autoimmunity. Conversely, we will discuss mechanisms by which activated T cells protect themselves against NK cell attack and outline the significance of this safeguard mechanism. PMID:27446081

  13. Interneuron progenitor transplantation to treat CNS dysfunction

    Directory of Open Access Journals (Sweden)

    Muhammad O Chohan

    2016-08-01

    Full Text Available Due to the inadequacy of endogenous repair mechanisms diseases of the nervous system remain a major challenge to scientists and clinicians. Stem cell based therapy is an exciting and viable strategy that has been shown to ameliorate or even reverse symptoms of CNS dysfunction in preclinical animal models. Of particular importance has been the use of GABAergic interneuron progenitors as a therapeutic strategy. Born in the neurogenic niches of the ventral telencephalon, interneuron progenitors retain their unique capacity to disperse, integrate and induce plasticity in adult host circuitries following transplantation. Here we discuss the potential of interneuron based transplantation strategies as it relates to CNS disease therapeutics. We also discuss mechanisms underlying their therapeutic efficacy and some of the challenges that face the field.

  14. Regulation of cell proliferation by G proteins.

    Science.gov (United States)

    Dhanasekaran, N; Tsim, S T; Dermott, J M; Onesime, D

    1998-09-17

    G Proteins provide signal transduction mechanisms to seven transmembrane receptors. Recent studies have indicated that the alpha-subunits as well as the betagamma-subunits of these proteins regulate several critical signaling pathways involved in cell proliferation, differentiation and apoptosis. Of the 17 alpha-subunits that have been cloned, at least ten of them have been shown to couple mitogenic signaling in fibroblast cells. Activating mutations in G alpha(s), G alpha(i)2, and G alpha12 have been correlated with different types of tumors. In addition, the ability of the betagamma-subunits to activate mitogenic pathways in different cell-types has been defined. The present review briefly summarizes the diverse and novel signaling pathways regulated by the alpha- as well as the betagamma-subunits of G proteins in regulating cell proliferation. PMID:9779986

  15. Glial Cell Regulation of Rhythmic Behavior

    Science.gov (United States)

    Jackson, F. Rob; Ng, Fanny S.; Sengupta, Sukanya; You, Samantha; Huang, Yanmei

    2015-01-01

    Brain glial cells, in particular astrocytes and microglia, secrete signaling molecules that regulate glia–glia or glia–neuron communication and synaptic activity. While much is known about roles of glial cells in nervous system development, we are only beginning to understand the physiological functions of such cells in the adult brain. Studies in vertebrate and invertebrate models, in particular mice and Drosophila, have revealed roles of glia–neuron communication in the modulation of complex behavior. This chapter emphasizes recent evidence from studies of rodents and Drosophila that highlight the importance of glial cells and similarities or differences in the neural circuits regulating circadian rhythms and sleep in the two models. The chapter discusses cellular, molecular, and genetic approaches that have been useful in these models for understanding how glia–neuron communication contributes to the regulation of rhythmic behavior. PMID:25707272

  16. Histamine and Immune Biomarkers in CNS Disorders

    Directory of Open Access Journals (Sweden)

    Ramón Cacabelos

    2016-01-01

    Full Text Available Neuroimmune dysregulation is a common phenomenon in different forms of central nervous system (CNS disorders. Cross-links between central and peripheral immune mechanisms appear to be disrupted as reflected by a series of immune markers (CD3, CD4, CD7, HLA-DR, CD25, CD28, and CD56 which show variability in brain disorders such as anxiety, depression, psychosis, stroke, Alzheimer’s disease, Parkinson’s disease, attention-deficit hyperactivity disorder, migraine, epilepsy, vascular dementia, mental retardation, cerebrovascular encephalopathy, multiple sclerosis, brain tumors, cranial nerve neuropathies, mental retardation, and posttraumatic brain injury. Histamine (HA is a pleiotropic monoamine involved in several neurophysiological functions, neuroimmune regulation, and CNS pathogenesis. Changes in brain HA show an age- and sex-related pattern, and alterations in brain HA levels are present in different CNS regions of patients with Alzheimer’s disease (AD. Brain HA in neuronal and nonneuronal compartments plays a dual role (neurotrophic versus neurotoxic in a tissue-specific manner. Pathogenic mechanisms associated with neuroimmune dysregulation in AD involve HA, interleukin-1β, and TNF-α, whose aberrant expression contributes to neuroinflammation as an aggravating factor for neurodegeneration and premature neuronal death.

  17. T-cell- and macrophage-mediated axon damage in the absence of a CNS-specific immune response: involvement of metalloproteinases.

    Science.gov (United States)

    Newman, T A; Woolley, S T; Hughes, P M; Sibson, N R; Anthony, D C; Perry, V H

    2001-11-01

    Recent evidence has highlighted the fact that axon injury is an important component of multiple sclerosis pathology. The issue of whether a CNS antigen-specific immune response is required to produce axon injury remains unresolved. We investigated the extent and time course of axon injury in a rodent model of a delayed-type hypersensitivity (DTH) reaction directed against the mycobacterium bacille Calmette-Guérin (BCG). Using MRI, we determined whether the ongoing axon injury is restricted to the period during which the blood-brain barrier is compromised. DTH lesions were initiated in adult rats by intracerebral injection of heat-killed BCG followed by a peripheral challenge with BCG. Our findings demonstrate that a DTH reaction to a non-CNS antigen within a CNS white matter tract leads to axon injury. Ongoing axon injury persisted throughout the 3-month period studied and was not restricted to the period of blood-brain barrier breakdown, as detected by MRI enhancing lesions. We have previously demonstrated that matrix metalloproteinases (MMPs) are upregulated in multiple sclerosis plaques and DTH lesions. In this study we demonstrated that microinjection of activated MMPs into the cortical white matter results in axon injury. Our results show that axon injury, possibly mediated by MMPs, is immunologically non-specific and may continue behind an intact blood-brain barrier.

  18. Disruption of microtubule integrity initiates mitosis during CNS repair.

    Science.gov (United States)

    Bossing, Torsten; Barros, Claudia S; Fischer, Bettina; Russell, Steven; Shepherd, David

    2012-08-14

    Mechanisms of CNS repair have vital medical implications. We show that traumatic injury to the ventral midline of the embryonic Drosophila CNS activates cell divisions to replace lost cells. A pilot screen analyzing transcriptomes of single cells during repair pointed to downregulation of the microtubule-stabilizing GTPase mitochondrial Rho (Miro) and upregulation of the Jun transcription factor Jun-related antigen (Jra). Ectopic Miro expression can prevent midline divisions after damage, whereas Miro depletion destabilizes cortical β-tubulin and increases divisions. Disruption of cortical microtubules, either by chemical depolymerization or by overexpression of monomeric tubulin, triggers ectopic mitosis in the midline and induces Jra expression. Conversely, loss of Jra renders midline cells unable to replace damaged siblings. Our data indicate that upon injury, the integrity of the microtubule cytoskeleton controls cell division in the CNS midline, triggering extra mitosis to replace lost cells. The conservation of the identified molecules suggests that similar mechanisms may operate in vertebrates.

  19. Neural stem cell derived tumourigenesis

    OpenAIRE

    Francesca Froldi; Milán Szuperák; Cheng, Louise Y.

    2015-01-01

    In the developing Drosophila CNS, two pools of neural stem cells, the symmetrically dividing progenitors in the neuroepithelium (NE) and the asymmetrically dividing neuroblasts (NBs) generate the majority of the neurons that make up the adult central nervous system (CNS). The generation of a correct sized brain depends on maintaining the fine balance between neural stem cell self-renewal and differentiation, which are regulated by cell-intrinsic and cell-extrinsic cues. In this review, we wil...

  20. Tip cells: master regulators of tubulogenesis?

    Science.gov (United States)

    Weavers, Helen; Skaer, Helen

    2014-07-01

    The normal development of an organ depends on the coordinated regulation of multiple cell activities. Focusing on tubulogenesis, we review the role of specialised cells or groups of cells that are selected from within tissue primordia and differentiate at the outgrowing tips or leading edge of developing tubules. Tip or leading cells develop distinctive patterns of gene expression that enable them to act both as sensors and transmitters of intercellular signalling. This enables them to explore the environment, respond to both tissue intrinsic signals and extrinsic cues from surrounding tissues and to regulate the behaviour of their neighbours, including the setting of cell fate, patterning cell division, inducing polarity and promoting cell movement and cell rearrangements by neighbour exchange. Tip cells are also able to transmit mechanical tension to promote tissue remodelling and, by interacting with the extracellular matrix, they can dictate migratory pathways and organ shape. Where separate tubular structures fuse to form networks, as in the airways of insects or the vascular system of vertebrates, specialised fusion tip cells act to interconnect disparate elements of the developing network. Finally, we consider their importance in the maturation of mature physiological function and in the development of disease.

  1. Physiology of cell volume regulation in vertebrates

    DEFF Research Database (Denmark)

    Hoffmann, Else K; Lambert, Ian H; Pedersen, Stine F

    2009-01-01

    cases, activation of volume regulatory osmolyte transport. After acute swelling, cell volume is regulated by the process of regulatory volume decrease (RVD), which involves the activation of KCl cotransport and of channels mediating K(+), Cl(-), and taurine efflux. Conversely, after acute shrinkage...... and their regulation by, e.g., membrane deformation, ionic strength, Ca(2+), protein kinases and phosphatases, cytoskeletal elements, GTP binding proteins, lipid mediators, and reactive oxygen species, upon changes in cell volume. We also discuss the nature of the upstream elements in volume sensing in vertebrate...

  2. When the tail can't wag the dog: the implications of CNS-intrinsic initiation of neuroinflammation

    Directory of Open Access Journals (Sweden)

    Monica J Carson

    2009-05-01

    Full Text Available The CNS (central nervous system is unquestionably the central organ that regulates directly or indirectly all physiological systems in the mammalian body. Yet, when considering the defence of the CNS from pathogens, the CNS has often been considered passive and subservient to the pro-inflammatory responses of the immune system. In this view, neuroinflammatory disorders are examples of when the tail (the immune system wags the dog (the CNS to the detriment of an individual's function and survival.

  3. Cell shape regulation through mechanosensory feedback control.

    Science.gov (United States)

    Mohan, Krithika; Luo, Tianzhi; Robinson, Douglas N; Iglesias, Pablo A

    2015-08-01

    Cells undergo controlled changes in morphology in response to intracellular and extracellular signals. These changes require a means for sensing and interpreting the signalling cues, for generating the forces that act on the cell's physical material, and a control system to regulate this process. Experiments on Dictyostelium amoebae have shown that force-generating proteins can localize in response to external mechanical perturbations. This mechanosensing, and the ensuing mechanical feedback, plays an important role in minimizing the effect of mechanical disturbances in the course of changes in cell shape, especially during cell division, and likely in other contexts, such as during three-dimensional migration. Owing to the complexity of the feedback system, which couples mechanical and biochemical signals involved in shape regulation, theoretical approaches can guide further investigation by providing insights that are difficult to decipher experimentally. Here, we present a computational model that explains the different mechanosensory and mechanoresponsive behaviours observed in Dictyostelium cells. The model features a multiscale description of myosin II bipolar thick filament assembly that includes cooperative and force-dependent myosin-actin binding, and identifies the feedback mechanisms hidden in the observed mechanoresponsive behaviours of Dictyostelium cells during micropipette aspiration experiments. These feedbacks provide a mechanistic explanation of cellular retraction and hence cell shape regulation. PMID:26224568

  4. Experimental autoimmune encephalomyelitis: Association with mutual regulation of RelA (p65)/NF-κB and phospho-IκB in the CNS

    International Nuclear Information System (INIS)

    Highlights: → The phosphorylation of RelA's inhibitory factor IκB and subsequent RelA activation are important to the disease process of EAE. → The expression of RelA and phospho-IκB was markedly increased in the initiation and during the progression of EAE. → TPCK-treated EAE mice showed lower incidence of EAE with less severe symptoms and quicker recovery than vehicle-treated EAE mice. → TPCK significantly suppressed the MOG35-55-specific T cell proliferation by reducing the production of IFN-γ and IL-17 cytokines in EAE. → The NF-κB cascade's activity increased gradually with the development of symptoms and brain pathology of EAE. -- Abstract: Recently emerging evidence that the NF-κB family plays an important role in autoimmune disease has produced very broad and sometimes paradoxical conclusions. In the present study, we elucidated that the activation of RelA (p65) of NF-κB and IκB dissociation assumes a distinct role in experimental autoimmune encephalomyelitis (EAE) progression by altering IκB phosphorylation and/or degradation. In the present study of factors that govern EAE, the presence and immunoreactivity of nuclear RelA and phospho-IκB were recorded at the initiation and peak stage, and degradation of IκBα progressed rapidly at an early stage then stabilized during recovery. The immunoreactivity to RelA and phospho-IκB occurred mainly in inflammatory cells and microglial cells but only slightly in astrocytes. Subsequently, the blockade of IκB dissociation from NF-κB reduced the severity of disease by decreasing antigen-specific T cell response and production of IL-17 in EAE. Thus, blocking the dissociation of IκB from NF-κB can be utilized as a strategy to inhibit the NF-κB signal pathway thereby to reduce the initiation, progression, and severity of EAE.

  5. Experimental autoimmune encephalomyelitis: Association with mutual regulation of RelA (p65)/NF-{kappa}B and phospho-I{kappa}B in the CNS

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Insun; Ha, Danbee [College of Veterinary Medicine and Applied Radiological Science Institute, Jeju National University, Jeju 690-756 (Korea, Republic of); Ahn, Ginnae [Department of Marine Life Science, Jeju National University, Jeju 690-756 (Korea, Republic of); Park, Eunjin; Joo, Haejin [College of Veterinary Medicine and Applied Radiological Science Institute, Jeju National University, Jeju 690-756 (Korea, Republic of); Jee, Youngheun, E-mail: yhjee@jejunu.ac.kr [College of Veterinary Medicine and Applied Radiological Science Institute, Jeju National University, Jeju 690-756 (Korea, Republic of)

    2011-07-29

    Highlights: {yields} The phosphorylation of RelA's inhibitory factor I{kappa}B and subsequent RelA activation are important to the disease process of EAE. {yields} The expression of RelA and phospho-I{kappa}B was markedly increased in the initiation and during the progression of EAE. {yields} TPCK-treated EAE mice showed lower incidence of EAE with less severe symptoms and quicker recovery than vehicle-treated EAE mice. {yields} TPCK significantly suppressed the MOG{sub 35-55}-specific T cell proliferation by reducing the production of IFN-{gamma} and IL-17 cytokines in EAE. {yields} The NF-{kappa}B cascade's activity increased gradually with the development of symptoms and brain pathology of EAE. -- Abstract: Recently emerging evidence that the NF-{kappa}B family plays an important role in autoimmune disease has produced very broad and sometimes paradoxical conclusions. In the present study, we elucidated that the activation of RelA (p65) of NF-{kappa}B and I{kappa}B dissociation assumes a distinct role in experimental autoimmune encephalomyelitis (EAE) progression by altering I{kappa}B phosphorylation and/or degradation. In the present study of factors that govern EAE, the presence and immunoreactivity of nuclear RelA and phospho-I{kappa}B were recorded at the initiation and peak stage, and degradation of I{kappa}B{alpha} progressed rapidly at an early stage then stabilized during recovery. The immunoreactivity to RelA and phospho-I{kappa}B occurred mainly in inflammatory cells and microglial cells but only slightly in astrocytes. Subsequently, the blockade of I{kappa}B dissociation from NF-{kappa}B reduced the severity of disease by decreasing antigen-specific T cell response and production of IL-17 in EAE. Thus, blocking the dissociation of I{kappa}B from NF-{kappa}B can be utilized as a strategy to inhibit the NF-{kappa}B signal pathway thereby to reduce the initiation, progression, and severity of EAE.

  6. Determining Immune System Suppression versus CNS Protection for Pharmacological Interventions in Autoimmune Demyelination.

    Science.gov (United States)

    Evonuk, Kirsten S; Moseley, Carson E; Doyle, Ryan E; Weaver, Casey T; DeSilva, Tara M

    2016-01-01

    A major hallmark of the autoimmune demyelinating disease multiple sclerosis (MS) is immune cell infiltration into the brain and spinal cord resulting in myelin destruction, which not only slows conduction of nerve impulses, but causes axonal injury resulting in motor and cognitive decline. Current treatments for MS focus on attenuating immune cell infiltration into the central nervous system (CNS). These treatments decrease the number of relapses, improving quality of life, but do not completely eliminate relapses so long-term disability is not improved. Therefore, therapeutic agents that protect the CNS are warranted. In both animal models as well as human patients with MS, T cell entry into the CNS is generally considered the initiating inflammatory event. In order to assess if a drug protects the CNS, any potential effects on immune cell infiltration or proliferation in the periphery must be ruled out. This protocol describes how to determine whether CNS protection observed after drug intervention is a consequence of attenuating CNS-infiltrating immune cells or blocking death of CNS cells during inflammatory insults. The ability to examine MS treatments that are protective to the CNS during inflammatory insults is highly critical for the advancement of therapeutic strategies since current treatments reduce, but do not completely eliminate, relapses (i.e., immune cell infiltration), leaving the CNS vulnerable to degeneration. PMID:27685467

  7. Mitochondrial Regulation of Cell Cycle and Proliferation

    OpenAIRE

    Antico Arciuch, Valeria Gabriela; Elguero, María Eugenia; Poderoso, Juan José; Carreras, María Cecilia

    2012-01-01

    Eukaryotic mitochondria resulted from symbiotic incorporation of α-proteobacteria into ancient archaea species. During evolution, mitochondria lost most of the prokaryotic bacterial genes and only conserved a small fraction including those encoding 13 proteins of the respiratory chain. In this process, many functions were transferred to the host cells, but mitochondria gained a central role in the regulation of cell proliferation and apoptosis, and in the modulation of metabolism; accordingly...

  8. Regulation of cell division in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, T.W.

    1992-01-01

    Cell division is arguably the most fundamental of all developmental processes. In higher plants, mitotic activity is largely confined to foci of patterned cell divisions called meristems. From these perpetually embryonic tissues arise the plant's essential organs of light capture, support, protection and reproduction. Once an adequate understanding of plant cell mitotic regulation is attained, unprecedented opportunities will ensue for analyzing and genetically controlling diverse aspects of development, including plant architecture, leaf shape, plant height, and root depth. The mitotic cycle in a variety of model eukaryotic systems in under the control of a regulatory network of striking evolutionary conservation. Homologues of the yeast cdc2 gene, its catalytic product, p34, and the cyclin regulatory subunits of the MPF complex have emerged as ubiquitous mitotic regulators. We have cloned cdc2-like and cyclin genes from pea. As in other eukaryotic model systems, p34 of Pisum sativum is a subunit of a high molecular weight complex which binds the fission yeast p13 protein and displays histone H1 kinase activity in vitro. Our primary objective in this study is to gain baseline information about the regulation of this higher plant cell division control complex in non-dividing, differentiated cells as well as in synchronous and asynchronous mitotic cells. We are investigating cdc2 and cyclin expression at the levels of protein abundance, protein phosphorylation and quaternary associations.

  9. Epigenetic regulation of the mammalian cell.

    Directory of Open Access Journals (Sweden)

    Keith Baverstock

    Full Text Available BACKGROUND: Understanding how mammalian cells are regulated epigenetically to express phenotype is a priority. The cellular phenotypic transition, induced by ionising radiation, from a normal cell to the genomic instability phenotype, where the ability to replicate the genotype accurately is compromised, illustrates important features of epigenetic regulation. Based on this phenomenon and earlier work we propose a model to describe the mammalian cell as a self assembled open system operating in an environment that includes its genotype, neighbouring cells and beyond. Phenotype is represented by high dimensional attractors, evolutionarily conditioned for stability and robustness and contingent on rules of engagement between gene products encoded in the genetic network. METHODOLOGY/FINDINGS: We describe how this system functions and note the indeterminacy and fluidity of its internal workings which place it in the logical reasoning framework of predicative logic. We find that the hypothesis is supported by evidence from cell and molecular biology. CONCLUSIONS: Epigenetic regulation and memory are fundamentally physical, as opposed to chemical, processes and the transition to genomic instability is an important feature of mammalian cells with probable fundamental relevance to speciation and carcinogenesis. A source of evolutionarily selectable variation, in terms of the rules of engagement between gene products, is seen as more likely to have greater prominence than genetic variation in an evolutionary context. As this epigenetic variation is based on attractor states phenotypic changes are not gradual; a phenotypic transition can involve the changed contribution of several gene products in a single step.

  10. Redox regulation in cancer stem cells

    Science.gov (United States)

    Reactive oxygen species (ROS) and ROS-dependent (redox regulation) signaling pathways and transcriptional activities are thought to be critical in stem cell self-renewal and differentiation during growth and organogenesis. Aberrant ROS burst and dysregulation of those ROS-dependent cellular processe...

  11. HDAC1 regulates the proliferation of radial glial cells in the developing Xenopus tectum.

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    Yi Tao

    Full Text Available In the developing central nervous system (CNS, progenitor cells differentiate into progeny to form functional neural circuits. Radial glial cells (RGs are a transient progenitor cell type that is present during neurogenesis. It is thought that a combination of neural trophic factors, neurotransmitters and electrical activity regulates the proliferation and differentiation of RGs. However, it is less clear how epigenetic modulation changes RG proliferation. We sought to explore the effect of histone deacetylase (HDAC activity on the proliferation of RGs in the visual optic tectum of Xenopus laevis. We found that the number of BrdU-labeled precursor cells along the ventricular layer of the tectum decrease developmentally from stage 46 to stage 49. The co-labeling of BrdU-positive cells with brain lipid-binding protein (BLBP, a radial glia marker, showed that the majority of BrdU-labeled cells along the tectal midline are RGs. BLBP-positive cells are also developmentally decreased with the maturation of the brain. Furthermore, HDAC1 expression is developmentally down-regulated in tectal cells, especially in the ventricular layer of the tectum. Pharmacological blockade of HDACs using Trichostatin A (TSA or Valproic acid (VPA decreased the number of BrdU-positive, BLBP-positive and co-labeling cells. Specific knockdown of HDAC1 by a morpholino (HDAC1-MO decreased the number of BrdU- and BLBP-labeled cells and increased the acetylation level of histone H4 at lysine 12 (H4K12. The visual deprivation-induced increase in BrdU- and BLBP-positive cells was blocked by HDAC1 knockdown at stage 49 tadpoles. These data demonstrate that HDAC1 regulates radial glia cell proliferation in the developing optical tectum of Xenopus laevis.

  12. Topological regulation of lipid balance in cells.

    Science.gov (United States)

    Drin, Guillaume

    2014-01-01

    Lipids are unevenly distributed within and between cell membranes, thus defining organelle identity. Such distribution relies on local metabolic branches and mechanisms that move lipids. These processes are regulated by feedback mechanisms that decipher topographical information in organelle membranes and then regulate lipid levels or flows. In the endoplasmic reticulum, the major lipid source, transcriptional regulators and enzymes sense changes in membrane features to modulate lipid production. At the Golgi apparatus, lipid-synthesizing, lipid-flippase, and lipid-transport proteins (LTPs) collaborate to control lipid balance and distribution within the membrane to guarantee remodeling processes crucial for vesicular trafficking. Open questions exist regarding LTPs, which are thought to be lipid sensors that regulate lipid synthesis or carriers that transfer lipids between organelles across long distances or in contact sites. A novel model is that LTPs, by exchanging two different lipids, exploit one lipid gradient between two distinct membranes to build a second lipid gradient. PMID:24606148

  13. Autophagic regulation of smooth muscle cell biology

    Science.gov (United States)

    Salabei, Joshua K.; Hill, Bradford G.

    2014-01-01

    Autophagy regulates the metabolism, survival, and function of numerous cell types, including those comprising the cardiovascular system. In the vasculature, changes in autophagy have been documented in atherosclerotic and restenotic lesions and in hypertensive vessels. The biology of vascular smooth muscle cells appears particularly sensitive to changes in the autophagic program. Recent evidence indicates that stimuli or stressors evoked during the course of vascular disease can regulate autophagic activity, resulting in modulation of VSMC phenotype and viability. In particular, certain growth factors and cytokines, oxygen tension, and pharmacological drugs have been shown to trigger autophagy in smooth muscle cells. Importantly, each of these stimuli has a redox component, typically associated with changes in the abundance of reactive oxygen, nitrogen, or lipid species. Collective findings support the hypothesis that autophagy plays a critical role in vascular remodeling by regulating smooth muscle cell phenotype transitions and by influencing the cellular response to stress. In this graphical review, we summarize current knowledge on the role of autophagy in the biology of the smooth muscle cell in (patho)physiology. PMID:25544597

  14. Autophagic regulation of smooth muscle cell biology

    Directory of Open Access Journals (Sweden)

    Joshua K. Salabei

    2015-04-01

    Full Text Available Autophagy regulates the metabolism, survival, and function of numerous cell types, including those comprising the cardiovascular system. In the vasculature, changes in autophagy have been documented in atherosclerotic and restenotic lesions and in hypertensive vessels. The biology of vascular smooth muscle cells appears particularly sensitive to changes in the autophagic program. Recent evidence indicates that stimuli or stressors evoked during the course of vascular disease can regulate autophagic activity, resulting in modulation of VSMC phenotype and viability. In particular, certain growth factors and cytokines, oxygen tension, and pharmacological drugs have been shown to trigger autophagy in smooth muscle cells. Importantly, each of these stimuli has a redox component, typically associated with changes in the abundance of reactive oxygen, nitrogen, or lipid species. Collective findings support the hypothesis that autophagy plays a critical role in vascular remodeling by regulating smooth muscle cell phenotype transitions and by influencing the cellular response to stress. In this graphical review, we summarize current knowledge on the role of autophagy in the biology of the smooth muscle cell in (pathophysiology.

  15. The regulation of apoptotic cell death

    Directory of Open Access Journals (Sweden)

    G.P. Amarante-Mendes

    1999-09-01

    Full Text Available Apoptosis is a fundamental biological phenomenon in which the death of a cell is genetically and biochemically regulated. Different molecules are involved in the regulation of the apoptotic process. Death receptors, coupled to distinct members of the caspases as well as other adapter molecules, are involved in the initiation of the stress signals (The Indictment. Members of the Bcl-2 family control at the mitochondrial level the decision between life and death (The Judgement. The effector caspases are responsible for all morphological and biochemical changes related to apoptosis including the "eat-me" signals perceived by phagocytes and neighboring cells (The Execution. Finally, apoptosis would have little biological significance without the recognition and removal of the dying cells (The Burial.

  16. The regulation of apoptotic cell death

    Directory of Open Access Journals (Sweden)

    Amarante-Mendes G.P.

    1999-01-01

    Full Text Available Apoptosis is a fundamental biological phenomenon in which the death of a cell is genetically and biochemically regulated. Different molecules are involved in the regulation of the apoptotic process. Death receptors, coupled to distinct members of the caspases as well as other adapter molecules, are involved in the initiation of the stress signals (The Indictment. Members of the Bcl-2 family control at the mitochondrial level the decision between life and death (The Judgement. The effector caspases are responsible for all morphological and biochemical changes related to apoptosis including the "eat-me" signals perceived by phagocytes and neighboring cells (The Execution. Finally, apoptosis would have little biological significance without the recognition and removal of the dying cells (The Burial.

  17. The Effect of the Uncariae Ramulus et Uncus on the Regeneration Following CNS Injury

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    Lee Jin-Goo

    2009-03-01

    Full Text Available Objective : Following central nervous system(CNS injury, inhibitory influences at the site of axonal damage occur. Glial cells become reactive and form a glial scar, gliosis. Also myelin debris such as MAG inhibits axonal regeneration. Astrocyte-rich gliosis relates with up-regulation of GFAP and CD81, and eventually becomes physical and mechanical barrier to axonal regeneration. MAG is one of several endogenous axon regeneration inhibitors that limit recovery from CNS injury and disease. It was reported that molecules that block such inhibitors enhanced axon regeneration and functional recovery. Recently it was reported that treatment with anti-CD81 antibodies enhanced functional recovery in the rat with spinal cord injury. So in this current study, the author investigated the effect of the water extract of Uncariae Ramulus et Uncus on the regulation of CD81, GFAP and MAG that increase when gliosis occurs. Methods : MTT assay was performed to examine cell viability, and cell-based ELISA, western blot and PCR were used to detect the expression of CD81, GFAP and MAG. Then also immunohistochemistry was performed to confirm in vivo. Results : Water extract of Uncariae Ramulus et Uncus showed relatively high cell viability at the concentration of 0.05%, 0.1% and 0.5%. The expression of CD81, GFAP and MAG in astrocytes was decreased after the administration of Uncariae Ramulus et Uncus water extract. These results was confirmed in the brain sections following cortical stab injury by immunohistochemistry. Conclusion : The authors observed that Uncariae Ramulus et Uncus significantly down-regulates the expression of CD81, GFAP and MAG. These results suggest that Uncariae Ramulus et Uncus can be a candidate to regenerate CNS injury.

  18. Mast cells as regulators of T cell responses

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    Silvia eBulfone-Paus

    2015-08-01

    Full Text Available Mast cells are recognized to participate in the regulation of innate and adaptive immune responses. Owing to their strategic location at the host-environment interface they control tissue homeostasis and are key cells for starting early host defence against intruders. Upon degranulation induced, e.g. by immunoglobulin E (IgE and allergen-mediated engagement of the high-affinity IgE receptor, complement or certain neuropeptide receptors, mast cells release a wide variety of preformed and newly synthesized products including proteases, lipid mediators, and many cytokines, chemokines, and growth factors. Interestingly, increasing evidence suggests a regulatory role for mast cells in inflammatory diseases via the regulation of T cell activities. Furthermore, rather than only serving as effector cells, mast cells are now recognized to induce T cell activation, recruitment, proliferation and cytokine secretion in an antigen-dependent manner and to impact on regulatory T cells. This review synthesizes recent developments in mast cell-T cell interactions, discusses their biological and clinical relevance, and explores recent controversies in this field of mast cell research.

  19. Autophagy in immune cell regulation and dysregulation.

    Science.gov (United States)

    Chaturvedi, Akanksha; Pierce, Susan K

    2009-09-01

    Autophagy is an ancient pathway required for cell and tissue homeostasis and differentiation. Initially thought to be a process leading to cell death, autophagy is currently viewed as a beneficial catabolic process that promotes cell survival under starvation conditions by sequestering components of the cytoplasm, including misfolded proteins, protein aggregates, and damaged organelles, and targeting them for lysosome-mediated degradation. In this way, autophagy plays a role in maintaining a balance between degradation and recycling of cellular material. The importance of autophagy is underscored by the fact that malfunctioning of this pathway results in neurodegeneration, cancer, susceptibility to microbial infection, and premature aging. Autophagy occurs in almost all cell types, including immune cells. Recent advances in the field suggest that autophagy plays a central role in regulating the immune system at multiple levels. In this review, we focus on recent developments in the area of autophagy-mediated modulation of immune responses. PMID:19671376

  20. Genetic models for CNS inflammation

    DEFF Research Database (Denmark)

    Owens, T; Wekerle, H; Antel, J

    2001-01-01

    The use of transgenic technology to over-express or prevent expression of genes encoding molecules related to inflammation has allowed direct examination of their role in experimental disease. This article reviews transgenic and knockout models of CNS demyelinating disease, focusing primarily on ...

  1. Basic Concepts of CNS Development.

    Science.gov (United States)

    Nowakowski, R. S.

    1987-01-01

    The goals of this review are to: (1) provide a set of concepts to aid in the understanding of complex processes which occur during central nervous system (CNS) development; (2) illustrate how they contribute to our knowlege of adult brain anatomy; and (3) delineate how modifications of normal developmental processes may affect the structure and…

  2. Nuclear myosin I regulates cell membrane tension

    Science.gov (United States)

    Venit, Tomáš; Kalendová, Alžběta; Petr, Martin; Dzijak, Rastislav; Pastorek, Lukáš; Rohožková, Jana; Malohlava, Jakub; Hozák, Pavel

    2016-01-01

    Plasma membrane tension is an important feature that determines the cell shape and influences processes such as cell motility, spreading, endocytosis and exocytosis. Unconventional class 1 myosins are potent regulators of plasma membrane tension because they physically link the plasma membrane with adjacent cytoskeleton. We identified nuclear myosin 1 (NM1) - a putative nuclear isoform of myosin 1c (Myo1c) - as a new player in the field. Although having specific nuclear functions, NM1 localizes predominantly to the plasma membrane. Deletion of NM1 causes more than a 50% increase in the elasticity of the plasma membrane around the actin cytoskeleton as measured by atomic force microscopy. This higher elasticity of NM1 knock-out cells leads to 25% higher resistance to short-term hypotonic environment and rapid cell swelling. In contrast, overexpression of NM1 in wild type cells leads to an additional 30% reduction of their survival. We have shown that NM1 has a direct functional role in the cytoplasm as a dynamic linker between the cell membrane and the underlying cytoskeleton, regulating the degree of effective plasma membrane tension. PMID:27480647

  3. Ulk4 Regulates Neural Stem Cell Pool.

    Science.gov (United States)

    Liu, Min; Guan, Zhenlong; Shen, Qin; Flinter, Frances; Domínguez, Laura; Ahn, Joo Wook; Collier, David A; O'Brien, Timothy; Shen, Sanbing

    2016-09-01

    The size of neural stem cell (NSC) pool at birth determines the starting point of adult neurogenesis. Aberrant neurogenesis is associated with major mental illness, in which ULK4 is proposed as a rare risk factor. Little is known about factors regulating the NSC pool, or function of the ULK4. Here, we showed that Ulk4(tm1a/tm1a) mice displayed a dramatically reduced NSC pool at birth. Ulk4 was expressed in a cell cycle-dependent manner and peaked in G2/M phases. Targeted disruption of the Ulk4 perturbed mid-neurogenesis and significantly reduced cerebral cortex in postnatal mice. Pathway analyses of dysregulated genes in Ulk4(tm1a/tm1a) mice revealed Ulk4 as a key regulator of cell cycle and NSC proliferation, partially through regulation of the Wnt signaling. In addition, we identified hemizygous deletion of ULK4 gene in 1.2/1,000 patients with pleiotropic symptoms including severe language delay and learning difficulties. ULK4, therefore, may significantly contribute to neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. Stem Cells 2016;34:2318-2331.

  4. Chondroitin sulfate proteoglycans regulate the growth, differentiation and migration of multipotent neural precursor cells through the integrin signaling pathway

    Directory of Open Access Journals (Sweden)

    Lü He-Zuo

    2009-10-01

    Full Text Available Abstract Background Neural precursor cells (NPCs are defined by their ability to proliferate, self-renew, and retain the potential to differentiate into neurons and glia. Deciphering the factors that regulate their behaviors will greatly aid in their use as potential therapeutic agents or targets. Chondroitin sulfate proteoglycans (CSPGs are prominent components of the extracellular matrix (ECM in the central nervous system (CNS and are assumed to play important roles in controlling neuronal differentiation and development. Results In the present study, we demonstrated that CSPGs were constitutively expressed on the NPCs isolated from the E16 rat embryonic brain. When chondroitinase ABC was used to abolish the function of endogenous CSPGs on NPCs, it induced a series of biological responses including the proliferation, differentiation and migration of NPCs, indicating that CSPGs may play a critical role in NPC development and differentiation. Finally, we provided evidence suggesting that integrin signaling pathway may be involved in the effects of CSPGs on NPCs. Conclusion The present study investigating the influence and mechanisms of CSPGs on the differentiation and migration of NPCs should help us to understand the basic biology of NPCs during CNS development and provide new insights into developing new strategies for the treatment of the neurological disorders in the CNS.

  5. ELECTROSTATIC CHARGE STIMULATES OXIDATIVE STRESS IN CNS MICROGLIA.

    Science.gov (United States)

    Nanometer size particles carry free radical activity on their surface and can create oxidative stress (OS)-mediated inflammatory changes upon impact. The oxidative burst signals the activation of phage-lineage cells such as peripheral macrophages, Kupffer cells and CNS microgl...

  6. Cell volume changes regulate slick (Slo2.1, but not slack (Slo2.2 K+ channels.

    Directory of Open Access Journals (Sweden)

    Maria A Tejada

    Full Text Available Slick (Slo2.1 and Slack (Slo2.2 channels belong to the family of high-conductance K+ channels and have been found widely distributed in the CNS. Both channels are activated by Na+ and Cl- and, in addition, Slick channels are regulated by ATP. Therefore, the roles of these channels in regulation of cell excitability as well as ion transport processes, like regulation of cell volume, have been hypothesized. It is the aim of this work to evaluate the sensitivity of Slick and Slack channels to small, fast changes in cell volume and to explore mechanisms, which may explain this type of regulation. For this purpose Slick and Slack channels were co-expressed with aquaporin 1 in Xenopus laevis oocytes and cell volume changes of around 5% were induced by exposure to hypotonic or hypertonic media. Whole-cell currents were measured by two electrode voltage clamp. Our results show that Slick channels are dramatically stimulated (196% of control by cell swelling and inhibited (57% of control by a decrease in cell volume. In contrast, Slack channels are totally insensitive to similar cell volume changes. The mechanism underlining the strong volume sensitivity of Slick channels needs to be further explored, however we were able to show that it does not depend on an intact actin cytoskeleton, ATP release or vesicle fusion. In conclusion, Slick channels, in contrast to the similar Slack channels, are the only high-conductance K+ channels strongly sensitive to small changes in cell volume.

  7. Regulation of satellite cell function in sarcopenia

    Directory of Open Access Journals (Sweden)

    Stephen E Alway

    2014-09-01

    Full Text Available The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell function that is impacted by the environment (niche of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse or rehabilitation in sarcopenic muscles. Nutritional intervention provides one therapeutic strategy to improve the satellite cell niche and systemic factors, with the goal of improving satellite cell function in aging muscles. Although many elderly persons consume various nutraceuticals with the hope of improving health, most of these compounds have not been thoroughly tested, and the impacts that they might have on sarcopenia, and satellite cell function are not clear. This review discusses data pertaining to the satellite cell responses and function in aging skeletal muscle, and the impact that three compounds: resveratrol, green tea catechins and β-Hydroxy-β-methylbutyrate have on regulating satellite cell function and therefore contributing to reducing sarcopenia or improving muscle mass after disuse in aging. The data suggest that these nutraceutical compounds improve satellite cell function during rehabilitative loading in animal models of aging after disuse (i.e., muscle regeneration. While these compounds have not been rigorously tested in humans, the data from animal models of aging provide a strong basis for conducting additional focused work to determine if these or other nutraceuticals can offset the muscle losses, or improve regeneration in sarcopenic muscles of older humans via improving satellite cell function.

  8. Regulation of satellite cell function in sarcopenia.

    Science.gov (United States)

    Alway, Stephen E; Myers, Matthew J; Mohamed, Junaith S

    2014-01-01

    The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell) function that is impacted by the environment (niche) of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse, or rehabilitation in sarcopenic muscles. Nutritional intervention provides one therapeutic strategy to improve the satellite cell niche and systemic factors, with the goal of improving satellite cell function in aging muscles. Although many elderly persons consume various nutraceuticals with the hope of improving health, most of these compounds have not been thoroughly tested, and the impacts that they might have on sarcopenia and satellite cell function are not clear. This review discusses data pertaining to the satellite cell responses and function in aging skeletal muscle, and the impact that three compounds: resveratrol, green tea catechins, and β-Hydroxy-β-methylbutyrate have on regulating satellite cell function and therefore contributing to reducing sarcopenia or improving muscle mass after disuse in aging. The data suggest that these nutraceutical compounds improve satellite cell function during rehabilitative loading in animal models of aging after disuse (i.e., muscle regeneration). While these compounds have not been rigorously tested in humans, the data from animal models of aging provide a strong basis for conducting additional focused work to determine if these or other nutraceuticals can offset the muscle losses, or improve regeneration in sarcopenic muscles of older humans via improving satellite cell function. PMID:25295003

  9. Targeting cell cycle regulators in hematologic malignancies

    Directory of Open Access Journals (Sweden)

    Eiman eAleem

    2015-04-01

    Full Text Available Hematologic malignancies represent the fourth most frequently diagnosed cancer in economically developed countries. In hematologic malignancies normal hematopoiesis is interrupted by uncontrolled growth of a genetically altered stem or progenitor cell (HSPC that maintains its ability of self-renewal. Cyclin-dependent kinases (CDKs not only regulate the mammalian cell cycle, but also influence other vital cellular processes, such as stem cell renewal, differentiation, transcription, epigenetic regulation, apoptosis, and DNA repair. Chromosomal translocations, amplification, overexpression and altered CDK activities have been described in different types of human cancer, which have made them attractive targets for pharmacological inhibition. Mouse models deficient for one or more CDKs have significantly contributed to our current understanding of the physiological functions of CDKs, as well as their roles in human cancer. The present review focuses on selected cell cycle kinases with recent emerging key functions in hematopoiesis and in hematopoietic malignancies, such as CDK6 and its role in MLL-rearranged leukemia and acute lymphocytic leukemia, CDK1 and its regulator WEE-1 in acute myeloid leukemia, and cyclin C/CDK8/CDK19 complexes in T-cell acute lymphocytic leukemia. The knowledge gained from gene knockout experiments in mice of these kinases is also summarized. An overview of compounds targeting these kinases, which are currently in clinical development in various solid tumors and hematopoietic malignances, is presented. These include the CDK4/CDK6 inhibitors (palbociclib, LEE011, LY2835219, pan-CDK inhibitors that target CDK1 (dinaciclib, flavopiridol, AT7519, TG02, P276-00, terampeprocol and RGB 286638 as well as the WEE-1 kinase inhibitor, MK-1775. The advantage of combination therapy of cell cycle inhibitors with conventional chemotherapeutic agents used in the treatment of AML, such as cytarabine, is discussed.

  10. Flavonoids: from cell cycle regulation to biotechnology.

    Science.gov (United States)

    Woo, Ho-Hyung; Jeong, Byeong Ryong; Hawes, Martha C

    2005-03-01

    Flavonoids have been proposed to play diverse roles in plant growth and development, including defense, symbiosis, pollen development and male fertility, polar auxin transport, and protection against ultraviolet radiation. Recently, a new role in cell cycle regulation has emerged. Genetic alteration of glucuronide metabolism by altered expression of a Pisum sativum UDP-glucuronosyltransferase (PsUGT1) results in an altered cell cycle in pea, alfalfa, and Arabidopsis. In alfalfa, altered expression of PsUGT1 results in accumulation of a flavonoid-like compound that suppresses growth of cultured cells. The results are consistent with the hypothesis that PsUGT1 functions by controlling cellular levels of a factor controlling cell cycle (FCC). PMID:15834800

  11. Gamma Interferon Signaling in Macrophage Lineage Cells Regulates Central Nervous System Inflammation and Chemokine Production ▿

    OpenAIRE

    Lin, Adora A.; Tripathi, Pulak K.; Sholl, Allyson; Jordan, Michael B.; Hildeman, David A.

    2009-01-01

    Intracranial (i.c.) infection of mice with lymphocytic choriomeningitis virus (LCMV) results in anorexic weight loss, mediated by T cells and gamma interferon (IFN-γ). Here, we assessed the role of CD4+ T cells and IFN-γ on immune cell recruitment and proinflammatory cytokine/chemokine production in the central nervous system (CNS) after i.c. LCMV infection. We found that T-cell-depleted mice had decreased recruitment of hematopoietic cells to the CNS and diminished levels of IFN-γ, CCL2 (MCP...

  12. Auxin regulation of cell polarity in plants.

    Science.gov (United States)

    Pan, Xue; Chen, Jisheng; Yang, Zhenbiao

    2015-12-01

    Auxin is well known to control pattern formation and directional growth at the organ/tissue levels via the nuclear TIR1/AFB receptor-mediated transcriptional responses. Recent studies have expanded the arena of auxin actions as a trigger or key regulator of cell polarization and morphogenesis. These actions require non-transcriptional responses such as changes in the cytoskeleton and vesicular trafficking, which are commonly regulated by ROP/Rac GTPase-dependent pathways. These findings beg for the question about the nature of auxin receptors that regulate these responses and renew the interest in ABP1 as a cell surface auxin receptor, including the work showing auxin-binding protein 1 (ABP1) interacts with the extracellular domain of the transmembrane kinase (TMK) receptor-like kinases in an auxin-dependent manner, as well as the debate on this auxin binding protein discovered about 40 years ago. This review highlights recent work on the non-transcriptional auxin signaling mechanisms underscoring cell polarity and shape formation in plants. PMID:26599954

  13. Main: 1CNS [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available 1CNS 大麦 Barley Hordeum vulgare l. 26 Kda Endochitinase 2 Precursor Hordeum Vulgare ...1.1; -.|PIR; A29104; A29104.|PIR; A38664; A38664.|PDB; 1CNS; X-ray; A/B=24-266.|PDB; 2BAA; X-ray; @=24-266.|...SSDYCTPSAQWPCAPGKRYYGRGPIQLSHNYNYGPAGRAIGVDLLANPDLVATDATVGFKTAIWFWMTAQPPKPSSHAVIAGQWSPSGADRAAGRVPGFGVITNIINGGIECGHGQDSRVADRIGFYKRYCDILGVGYGNNLDCYSQRPFA barley_1CNS.jpg ...

  14. Casein Kinase 1δ Is an APC/CCdh1 Substrate that Regulates Cerebellar Granule Cell Neurogenesis

    Directory of Open Access Journals (Sweden)

    Clara Penas

    2015-04-01

    Full Text Available Although casein kinase 1δ (CK1δ is at the center of multiple signaling pathways, its role in the expansion of CNS progenitor cells is unknown. Using mouse cerebellar granule cell progenitors (GCPs as a model for brain neurogenesis, we demonstrate that the loss of CK1δ or treatment of GCPs with a highly selective small molecule inhibits GCP expansion. In contrast, CK1δ overexpression increases GCP proliferation. Thus, CK1δ appears to regulate GCP neurogenesis. CK1δ is targeted for proteolysis via the anaphase-promoting complex/cyclosome (APC/CCdh1 ubiquitin ligase, and conditional deletion of the APC/CCdh1 activator Cdh1 in cerebellar GCPs results in higher levels of CK1δ. APC/CCdh1 also downregulates CK1δ during cell-cycle exit. Therefore, we conclude that APC/CCdh1 controls CK1δ levels to balance proliferation and cell-cycle exit in the developing CNS. Similar studies in medulloblastoma cells showed that CK1δ holds promise as a therapeutic target.

  15. CNS infections in immunocompromised patients

    International Nuclear Information System (INIS)

    CNS infections caused by infective agents are rare in immunocompetent hosts, but more frequent in immunocompromised patients. In addition, the spectrum of causative agents is completely different. There are no pathognomonic alterations in radiologic imaging, even in clinically severely ill patients imaging is often non-specific or inconspicious. This article gives a review of the most frequent infective agents and image alterations. Modern radiology is not yet able to replace the gold standard of pathogen detection. (orig.)

  16. CNP is required for maintenance of axon-glia interactions at nodes of Ranvier in the CNS.

    Science.gov (United States)

    Rasband, Matthew N; Tayler, Jane; Kaga, Yoshimi; Yang, Yang; Lappe-Siefke, Corinna; Nave, Klaus-Armin; Bansal, Rashmi

    2005-04-01

    Axoglial interactions underlie the clustering of ion channels and of cell adhesion molecules, regulate gene expression, and control cell survival. We report that Cnp1-null mice, lacking expression of the myelin protein cyclic nucleotide phosphodiesterase (CNP), have disrupted axoglial interactions in the central nervous system (CNS). Nodal sodium channels (Nav) and paranodal adhesion proteins (Caspr) are initially clustered normally, but become progressively disorganized with age. These changes are characterized by mislocalized Caspr immunostaining, combined with a decrease of clustered Na+ channels, and occur before axonal degeneration and microglial invasion, both prominent in older Cnp1-null mice. We suggest that CNP is a glial protein required for maintaining the integrity of paranodes and that disrupted axoglial signaling at this site underlies progressive axonal degeneration, observed later in the CNS of Cnp1-null mice. PMID:15657937

  17. Redox Regulation in Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Shijie Ding

    2015-01-01

    Full Text Available Reactive oxygen species (ROS and ROS-dependent (redox regulation signaling pathways and transcriptional activities are thought to be critical in stem cell self-renewal and differentiation during growth and organogenesis. Aberrant ROS burst and dysregulation of those ROS-dependent cellular processes are strongly associated with human diseases including many cancers. ROS levels are elevated in cancer cells partially due to their higher metabolism rate. In the past 15 years, the concept of cancer stem cells (CSCs has been gaining ground as the subpopulation of cancer cells with stem cell-like properties and characteristics have been identified in various cancers. CSCs possess low levels of ROS and are responsible for cancer recurrence after chemotherapy or radiotherapy. Unfortunately, how CSCs control ROS production and scavenging and how ROS-dependent signaling pathways contribute to CSCs function remain poorly understood. This review focuses on the role of redox balance, especially in ROS-dependent cellular processes in cancer stem cells (CSCs. We updated recent advances in our understanding of ROS generation and elimination in CSCs and their effects on CSC self-renewal and differentiation through modulating signaling pathways and transcriptional activities. The review concludes that targeting CSCs by manipulating ROS metabolism/dependent pathways may be an effective approach for improving cancer treatment.

  18. Induction of Golli-MBP Expression in CNS Macrophages During Acute LPS-Induced CNS Inflammation and Experimental Autoimmune Encephalomyelitis (EAE

    Directory of Open Access Journals (Sweden)

    Tracey L. Papenfuss

    2007-01-01

    Full Text Available Microglia are the tissue macrophages of the CNS. Microglial activation coupled with macrophage infiltration is a common feature of many classic neurodegenerative disorders. The absence of cell-type specific markers has confounded and complicated the analysis of cell-type specific contributions toward the onset, progression, and remission of neurodegeneration. Molecular screens comparing gene expression in cultured microglia and macrophages identified Golli-myelin basic protein (MBP as a candidate molecule enriched in peripheral macrophages. In situ hybridization analysis of LPS/IFNg and experimental autoimmune encephalomyelitis (EAE–induced CNS inflammation revealed that only a subset of CNS macrophages express Golli-MBP. Interestingly, the location and morphology of Golli-MBP+ CNS macrophages differs between these two models of CNS inflammation. These data demonstrate the difficulties of extending in vitro observations to in vivo biology and concretely illustrate the complex heterogeneity of macrophage activation states present in region- and stage-specific phases of CNS inflammation. Taken altogether, these are consistent with the emerging picture that the phenotype of CNS macrophages is actively defined by their molecular interactions with the CNS microenvironment.

  19. Drugs acting on central nervous system (CNS) targets as leads for non-CNS targets

    OpenAIRE

    Kharkar, Prashant S.

    2014-01-01

    Innovative drug discovery approaches are currently needed to rejuvenate the shrinking product pipelines of the pharmaceutical companies across the globe. Here a theme is presented – the use of central nervous system (CNS) drugs as leads for non-CNS targets. The approach is related to the use of existing drugs for new indications. Suitable chemical modifications of the CNS drugs abolish their CNS penetration. These novel analogs may then be screened for activity against non-CNS targets. Carefu...

  20. Transport and regulation mechanism of the colloidal gold liposomes in the brain microvascular endothelial cells

    Institute of Scientific and Technical Information of China (English)

    WANG Lipeng; CHANG Yanzhong

    2015-01-01

    Objective:Blood-brain barrier is the key barrier of brain in the innate immune. It can prevent the harmful substances from the blood into the brain. In order to keep the brain in a relatively stable environment and maintain the normal function of the nervous system, it can also pump harmful substances or excess substances outside the brain selectively. Among them, brain microvascular endothelial cell tissue is a key part in the blood-brain barrier's function. The number of the patients with central nervous system ( CNS) diseases increased year by year. The therapeutic drug is usually inhibited by the blood-brain barrier and is difficult to work. Therefore, how to modify the drug and to make it easier to cross the blood brain barrier is the key point to cure CNS. At present, more than 95% research focus only on how nano drugs can enter the cell, the way and efficiency to enter the cell and the research of effect of nano drug etc. For the process of drug carrier in endocytosis, intracellular transport and release and regulation of research are rarely reported. Clathrin and P-glycoprotein are related protein in endo-cytosis and exocytosis with nano drug. Clathrin is located on the plasma membrane. It participates in endocytosis of some nutrients, and maybe the entry into the cell of some drugs. P-glycoprotein is located in the membrane of cer-ebral capillary endothelial cells. It can efflux drugs relying on ATP. Although there is a certain understanding of the cell in the inner swallow and efflux. But the process of the liposome drug is not clear. To solve the above prob-lems, using colloidal gold liposome nano materials to trace liposome's transport and regulation mechanism in brain microvascular endothelial cells, and study endocytosis, release, distribution and regulation mechanism of nano lipo-somes in brain microvascular. The solution of this problem can guide to construct reasonable drug carrier, and look forward to clarifing the molecular basis and mechanism of

  1. Cell shape regulates global histone acetylation in human mammaryepithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Le Beyec, Johanne; Xu, Ren; Lee, Sun-Young; Nelson, Celeste M.; Rizki, Aylin; Alcaraz, Jordi; Bissell, Mina J.

    2007-02-28

    Extracellular matrix (ECM) regulates cell morphology and gene expression in vivo; these relationships are maintained in three-dimensional (3D) cultures of mammary epithelial cells. In the presence of laminin-rich ECM (lrECM), mammary epithelial cells round up and undergo global histone deacetylation, a process critical for their functional differentiation. However, it remains unclear whether lrECM-dependent cell rounding and global histone deacetylation are indeed part of a common physical-biochemical pathway. Using 3D cultures as well as nonadhesive and micropatterned substrata, here we showed that the cell 'rounding' caused by lrECM was sufficient to induce deacetylation of histones H3 and H4 in the absence of biochemical cues. Microarray and confocal analysis demonstrated that this deacetylation in 3D culture is associated with a global increase in chromatin condensation and a reduction in gene expression. Whereas cells cultured on plastic substrata formed prominent stress fibers, cells grown in 3D lrECM or on micropatterns lacked these structures. Disruption of the actin cytoskeleton with cytochalasin D phenocopied the lrECM-induced cell rounding and histone deacetylation. These results reveal a novel link between ECM-controlled cell shape and chromatin structure, and suggest that this link is mediated by changes in the actin cytoskeleton.

  2. Mechanical regulation of mesenchymal stem cell differentiation.

    Science.gov (United States)

    Steward, Andrew J; Kelly, Daniel J

    2015-12-01

    Biophysical cues play a key role in directing the lineage commitment of mesenchymal stem cells or multipotent stromal cells (MSCs), but the mechanotransductive mechanisms at play are still not fully understood. This review article first describes the roles of both substrate mechanics (e.g. stiffness and topography) and extrinsic mechanical cues (e.g. fluid flow, compression, hydrostatic pressure, tension) on the differentiation of MSCs. A specific focus is placed on the role of such factors in regulating the osteogenic, chondrogenic, myogenic and adipogenic differentiation of MSCs. Next, the article focuses on the cellular components, specifically integrins, ion channels, focal adhesions and the cytoskeleton, hypothesized to be involved in MSC mechanotransduction. This review aims to illustrate the strides that have been made in elucidating how MSCs sense and respond to their mechanical environment, and also to identify areas where further research is needed.

  3. Exercise regulates breast cancer cell viability

    DEFF Research Database (Denmark)

    Dethlefsen, Christine; Lillelund, Christian; Midtgaard, Julie;

    2016-01-01

    Purpose: Exercise decreases breast cancer risk and disease recurrence, but the underlying mechanisms are unknown. Training adaptations in systemic factors have been suggested as mediating causes. We aimed to examine if systemic adaptations to training over time, or acute exercise responses......, in breast cancer survivors could regulate breast cancer cell viability in vitro. Methods: Blood samples were collected from breast cancer survivors, partaking in either a 6-month training intervention or across a 2 h acute exercise session. Changes in training parameters and systemic factors were evaluated...... and pre/post exercise-conditioned sera from both studies were used to stimulate breast cancer cell lines (MCF-7, MDA-MB-231) in vitro. Results: Six months of training increased VO2peak (16.4 %, p

  4. How Do Meningeal Lymphatic Vessels Drain the CNS?

    Science.gov (United States)

    Raper, Daniel; Louveau, Antoine; Kipnis, Jonathan

    2016-09-01

    The many interactions between the nervous and the immune systems, which are active in both physiological and pathological states, have recently become more clearly delineated with the discovery of a meningeal lymphatic system capable of carrying fluid, immune cells, and macromolecules from the central nervous system (CNS) to the draining deep cervical lymph nodes. However, the exact localization of the meningeal lymphatic vasculature and the path of drainage from the cerebrospinal fluid (CSF) to the lymphatics remain poorly understood. Here, we discuss the potential differences between peripheral and CNS lymphatic vessels and examine the purported mechanisms of CNS lymphatic drainage, along with how these may fit into established patterns of CSF flow. PMID:27460561

  5. Identification of new therapeutic targets for prevention of CNS inflammation

    DEFF Research Database (Denmark)

    Owens, Trevor

    2002-01-01

    Multiple sclerosis (MS) is a disease of complex pathologies, which involves infiltration by CD4(+) and CD8(+) T cells of and response within the central nervous system. Expression in the CNS of cytokines, reactive nitrogen species and costimulator molecules have all been described in MS. Notably,...

  6. GATA2 regulates dendritic cell differentiation.

    Science.gov (United States)

    Onodera, Koichi; Fujiwara, Tohru; Onishi, Yasushi; Itoh-Nakadai, Ari; Okitsu, Yoko; Fukuhara, Noriko; Ishizawa, Kenichi; Shimizu, Ritsuko; Yamamoto, Masayuki; Harigae, Hideo

    2016-07-28

    Dendritic cells (DCs) are critical immune response regulators; however, the mechanism of DC differentiation is not fully understood. Heterozygous germ line GATA2 mutations induce GATA2-deficiency syndrome, characterized by monocytopenia, a predisposition to myelodysplasia/acute myeloid leukemia, and a profoundly reduced DC population, which is associated with increased susceptibility to viral infections, impaired phagocytosis, and decreased cytokine production. To define the role of GATA2 in DC differentiation and function, we studied Gata2 conditional knockout and haploinsufficient mice. Gata2 conditional deficiency significantly reduced the DC count, whereas Gata2 haploinsufficiency did not affect this population. GATA2 was required for the in vitro generation of DCs from Lin(-)Sca-1(+)Kit(+) cells, common myeloid-restricted progenitors, and common dendritic cell precursors, but not common lymphoid-restricted progenitors or granulocyte-macrophage progenitors, suggesting that GATA2 functions in the myeloid pathway of DC differentiation. Moreover, expression profiling demonstrated reduced expression of myeloid-related genes, including mafb, and increased expression of T-lymphocyte-related genes, including Gata3 and Tcf7, in Gata2-deficient DC progenitors. In addition, GATA2 was found to bind an enhancer element 190-kb downstream region of Gata3, and a reporter assay exhibited significantly reduced luciferase activity after adding this enhancer region to the Gata3 promoter, which was recovered by GATA sequence deletion within Gata3 +190. These results suggest that GATA2 plays an important role in cell-fate specification toward the myeloid vs T-lymphocyte lineage by regulating lineage-specific transcription factors in DC progenitors, thereby contributing to DC differentiation. PMID:27259979

  7. Epigenetic regulation of hematopoietic stem cell aging

    International Nuclear Information System (INIS)

    Aging is invariably associated with alterations of the hematopoietic stem cell (HSC) compartment, including loss of functional capacity, altered clonal composition, and changes in lineage contribution. Although accumulation of DNA damage occurs during HSC aging, it is unlikely such consistent aging phenotypes could be solely attributed to changes in DNA integrity. Another mechanism by which heritable traits could contribute to the changes in the functional potential of aged HSCs is through alterations in the epigenetic landscape of adult stem cells. Indeed, recent studies on hematopoietic stem cells have suggested that altered epigenetic profiles are associated with HSC aging and play a key role in modulating the functional potential of HSCs at different stages during ontogeny. Even small changes of the epigenetic landscape can lead to robustly altered expression patterns, either directly by loss of regulatory control or through indirect, additive effects, ultimately leading to transcriptional changes of the stem cells. Potential drivers of such changes in the epigenetic landscape of aged HSCs include proliferative history, DNA damage, and deregulation of key epigenetic enzymes and complexes. This review will focus largely on the two most characterized epigenetic marks – DNA methylation and histone modifications – but will also discuss the potential role of non-coding RNAs in regulating HSC function during aging

  8. Prostaglandin E2 regulates hematopoietic stem cell

    International Nuclear Information System (INIS)

    Prostaglandin E2 (PGE2) is a bioactive lipid molecule produced by cyclooxygenase (COX), which plays an important role on hematopoiesis. While it can block differentiation of myeloid progenitors but enhance proliferation of erythroid progenitors. Recent research found that PGE2 have the effects on hematopoietic stem cell (HSC) function and these effects were independent from effects on progenitor cells. Exposure of HSC cells to PGE2 in vitro can increase homing efficiency of HSC to the murine bone marrow compartment and decrease HSC apoptosis, meanwhile increase long-term stem cell engraftment. In-vivo treatment with PGE2 expands short-term HSC and engraftment in murine bone marrow but not long-term HSC.In addition, PGE2 increases HSC survival after radiation injury and enhance hematopoietic recovery, resulting maintains hematopoietic homeostasis. PGE2 regulates HSC homeostasis by reactive oxygen species and Wnt pathway. Clinical beneficial of 16, 16-dimethyl-prostaglandin E2 treatment to enhance engraftment of umbilical cord blood suggest important improvements to therapeutic strategies. (authors)

  9. Molecular regulation of pancreatic stellate cell function

    Directory of Open Access Journals (Sweden)

    Jaster Robert

    2004-10-01

    Full Text Available Abstract Until now, no specific therapies are available to inhibit pancreatic fibrosis, a constant pathological feature of chronic pancreatitis and pancreatic cancer. One major reason is the incomplete knowledge of the molecular principles underlying fibrogenesis in the pancreas. In the past few years, evidence has been accumulated that activated pancreatic stellate cells (PSCs are the predominant source of extracellular matrix (ECM proteins in the diseased organ. PSCs are vitamin A-storing, fibroblast-like cells with close morphological and biochemical similarities to hepatic stellate cells (also known as Ito-cells. In response to profibrogenic mediators such as various cytokines, PSCs undergo an activation process that involves proliferation, exhibition of a myofibroblastic phenotype and enhanced production of ECM proteins. The intracellular mediators of activation signals, and their antagonists, are only partially known so far. Recent data suggest an important role of enzymes of the mitogen-activated protein kinase family in PSC activation. On the other hand, ligands of the nuclear receptor PPARγ (peroxisome proliferator-activated receptor γ stimulate maintenance of a quiescent PSC phenotype. In the future, targeting regulators of the PSC activation process might become a promising approach for the treatment of pancreatic fibrosis.

  10. Epigenetic regulation of hematopoietic stem cell aging

    Energy Technology Data Exchange (ETDEWEB)

    Beerman, Isabel, E-mail: isabel.beerman@childrens.harvard.edu [Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138 (United States); Department of Pediatrics, Harvard Medical School, Boston, MA 02115 (United States); Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children' s Hospital, MA 02116 (United States); Rossi, Derrick J. [Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138 (United States); Department of Pediatrics, Harvard Medical School, Boston, MA 02115 (United States); Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children' s Hospital, MA 02116 (United States)

    2014-12-10

    Aging is invariably associated with alterations of the hematopoietic stem cell (HSC) compartment, including loss of functional capacity, altered clonal composition, and changes in lineage contribution. Although accumulation of DNA damage occurs during HSC aging, it is unlikely such consistent aging phenotypes could be solely attributed to changes in DNA integrity. Another mechanism by which heritable traits could contribute to the changes in the functional potential of aged HSCs is through alterations in the epigenetic landscape of adult stem cells. Indeed, recent studies on hematopoietic stem cells have suggested that altered epigenetic profiles are associated with HSC aging and play a key role in modulating the functional potential of HSCs at different stages during ontogeny. Even small changes of the epigenetic landscape can lead to robustly altered expression patterns, either directly by loss of regulatory control or through indirect, additive effects, ultimately leading to transcriptional changes of the stem cells. Potential drivers of such changes in the epigenetic landscape of aged HSCs include proliferative history, DNA damage, and deregulation of key epigenetic enzymes and complexes. This review will focus largely on the two most characterized epigenetic marks – DNA methylation and histone modifications – but will also discuss the potential role of non-coding RNAs in regulating HSC function during aging.

  11. LRP1 expression in microglia is protective during CNS autoimmunity

    OpenAIRE

    Chuang, Tzu-Ying; Guo, Yong; Seki, Scott M.; Rosen, Abagail M.; Johanson, David M.; Mandell, James W.; Lucchinetti, Claudia F.; Gaultier, Alban

    2016-01-01

    Multiple sclerosis is a devastating neurological disorder characterized by the autoimmune destruction of the central nervous system myelin. While T cells are known orchestrators of the immune response leading to MS pathology, the precise contribution of CNS resident and peripheral infiltrating myeloid cells is less well described. Here, we explore the myeloid cell function of Low-density lipoprotein receptor-related protein-1 (LRP1), a scavenger receptor involved in myelin clearance and the i...

  12. Adrenomedullin as a Growth and Cell Fate Regulatory Factor for Adult Neural Stem Cells

    OpenAIRE

    Sonia Martínez-Herrero; Ignacio M Larráyoz; Laura Ochoa-Callejero; Josune García-Sanmartín; Alfredo Martínez

    2012-01-01

    The use of stem cells as a strategy for tissue repair and regeneration is one of the biomedical research areas that has attracted more interest in the past few years. Despite the classic belief that the central nervous system (CNS) was immutable, now it is well known that cell turnover occurs in the mature CNS. Postnatal neurogenesis is subjected to tight regulation by many growth factors, cell signals, and transcription factors. An emerging molecule involved in this process is adrenomedullin...

  13. Insulin/IGF-regulated size scaling of neuroendocrine cells expressing the bHLH transcription factor Dimmed in Drosophila.

    Directory of Open Access Journals (Sweden)

    Jiangnan Luo

    Full Text Available Neurons and other cells display a large variation in size in an organism. Thus, a fundamental question is how growth of individual cells and their organelles is regulated. Is size scaling of individual neurons regulated post-mitotically, independent of growth of the entire CNS? Although the role of insulin/IGF-signaling (IIS in growth of tissues and whole organisms is well established, it is not known whether it regulates the size of individual neurons. We therefore studied the role of IIS in the size scaling of neurons in the Drosophila CNS. By targeted genetic manipulations of insulin receptor (dInR expression in a variety of neuron types we demonstrate that the cell size is affected only in neuroendocrine cells specified by the bHLH transcription factor DIMMED (DIMM. Several populations of DIMM-positive neurons tested displayed enlarged cell bodies after overexpression of the dInR, as well as PI3 kinase and Akt1 (protein kinase B, whereas DIMM-negative neurons did not respond to dInR manipulations. Knockdown of these components produce the opposite phenotype. Increased growth can also be induced by targeted overexpression of nutrient-dependent TOR (target of rapamycin signaling components, such as Rheb (small GTPase, TOR and S6K (S6 kinase. After Dimm-knockdown in neuroendocrine cells manipulations of dInR expression have significantly less effects on cell size. We also show that dInR expression in neuroendocrine cells can be altered by up or down-regulation of Dimm. This novel dInR-regulated size scaling is seen during postembryonic development, continues in the aging adult and is diet dependent. The increase in cell size includes cell body, axon terminations, nucleus and Golgi apparatus. We suggest that the dInR-mediated scaling of neuroendocrine cells is part of a plasticity that adapts the secretory capacity to changing physiological conditions and nutrient-dependent organismal growth.

  14. Fulminant lymphocytic choriomeningitis virus-induced inflammation of the CNS involves a cytokine-chemokine-cytokine-chemokine cascade

    DEFF Research Database (Denmark)

    Christensen, Jeanette Erbo; Simonsen, Stine; Fenger, Christina;

    2009-01-01

    Intracerebral inoculation of immunocompetent mice with lymphocytic choriomeningitis virus (LCMV) normally results in fatal CD8+ T cell mediated meningoencephalitis. However, in CXCL10-deficient mice, the virus-induced CD8+ T cell accumulation in the neural parenchyma is impaired, and only 30......-50% of the mice succumb to the infection. Similar results are obtained in mice deficient in the matching chemokine receptor, CXCR3. Together, these findings point to a key role for CXCL10 in regulating the severity of the LCMV-induced inflammatory process. For this reason, we now address the mechanisms regulating...... the expression of CXCL10 in the CNS of LCMV-infected mice. Using mice deficient in type I IFN receptor, type II IFN receptor, or type II IFN, as well as bone marrow chimeras expressing CXCL10 only in resident cells or only in bone marrow-derived cells, we analyzed the up-stream regulation as well as the cellular...

  15. Stem cell therapy for central nerve system injuries:glial cells hold the key

    Institute of Scientific and Technical Information of China (English)

    Li Xiao; Chikako Saiki; Ryoji Ide

    2014-01-01

    Mammalian adult central nerve system (CNS) injuries are devastating because of the intrinsic dififculties for effective neuronal regeneration. The greatest problem to be overcome for CNS recovery is the poor regeneration of neurons and myelin-forming cells, oligodendrocytes. En-dogenous neural progenitors and transplanted exogenous neuronal stem cells can be the source for neuronal regeneration. However, because of the harsh local microenvironment, they usually have very low efifcacy for functional neural regeneration which cannot compensate for the loss of neurons and oligodendrocytes. Glial cells (including astrocytes, microglia, oligodendrocytes and NG2 glia) are the majority of cells in CNS that provide support and protection for neurons. Inside the local microenvironment, glial cells largely inlfuence local and transplanted neural stem cells survival and fates. This review critically analyzes current ifnding of the roles of glial cells in CNS regeneration, and highlights strategies for regulating glial cells’ behavior to create a permis-sive microenvironment for neuronal stem cells.

  16. Animal models of CNS disorders.

    Science.gov (United States)

    McGonigle, Paul

    2014-01-01

    There is intense interest in the development and application of animal models of CNS disorders to explore pathology and molecular mechanisms, identify potential biomarkers, and to assess the therapeutic utility, estimate safety margins and establish pharmacodynamic and pharmacokinetic parameters of new chemical entities (NCEs). This is a daunting undertaking, due to the complex and heterogeneous nature of these disorders, the subjective and sometimes contradictory nature of the clinical endpoints and the paucity of information regarding underlying molecular mechanisms. Historically, these models have been invaluable in the discovery of therapeutics for a range of disorders including anxiety, depression, schizophrenia, and Parkinson's disease. Recently, however, they have been increasingly criticized in the wake of numerous clinical trial failures of NCEs with promising preclinical profiles. These failures have resulted from a number of factors including inherent limitations of the models, over-interpretation of preclinical results and the complex nature of clinical trials for CNS disorders. This review discusses the rationale, strengths, weaknesses and predictive validity of the most commonly used models for psychiatric, neurodegenerative and neurological disorders as well as critical factors that affect the variability and reproducibility of these models. It also addresses how progress in molecular genetics and the development of transgenic animals has fundamentally changed the approach to neurodegenerative disorder research. To date, transgenic animal models\\have not been the panacea for drug discovery that many had hoped for. However continual refinement of these models is leading to steady progress with the promise of eventual therapeutic breakthroughs. PMID:23811310

  17. Molecular regulation of plant cell wall extensibility

    Science.gov (United States)

    Cosgrove, D. J.

    1998-01-01

    Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

  18. Cell fate control in the developing central nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Guérout, Nicolas; Li, Xiaofei; Barnabé-Heider, Fanie, E-mail: Fanie.Barnabe-Heider@ki.se

    2014-02-01

    The principal neural cell types forming the mature central nervous system (CNS) are now understood to be diverse. This cellular subtype diversity originates to a large extent from the specification of the earlier proliferating progenitor populations during development. Here, we review the processes governing the differentiation of a common neuroepithelial cell progenitor pool into mature neurons, astrocytes, oligodendrocytes, ependymal cells and adult stem cells. We focus on studies performed in mice and involving two distinct CNS structures: the spinal cord and the cerebral cortex. Understanding the origin, specification and developmental regulators of neural cells will ultimately impact comprehension and treatments of neurological disorders and diseases. - Highlights: • Similar mechanisms regulate cell fate in different CNS cell types and structures. • Cell fate regulators operate in a spatial–temporal manner. • Different neural cell types rely on the generation of a diversity of progenitor cells. • Cell fate decision is dictated by the integration of intrinsic and extrinsic signals.

  19. MicroRNA Regulation of Brain Tumour Initiating Cells in Central Nervous System Tumours

    Directory of Open Access Journals (Sweden)

    Neha Garg

    2015-01-01

    Full Text Available CNS tumours occur in both pediatric and adult patients and many of these tumours are associated with poor clinical outcome. Due to a paradigm shift in thinking for the last several years, these tumours are now considered to originate from a small population of stem-like cells within the bulk tumour tissue. These cells, termed as brain tumour initiating cells (BTICs, are perceived to be regulated by microRNAs at the posttranscriptional/translational levels. Proliferation, stemness, differentiation, invasion, angiogenesis, metastasis, apoptosis, and cell cycle constitute some of the significant processes modulated by microRNAs in cancer initiation and progression. Characterization and functional studies on oncogenic or tumour suppressive microRNAs are made possible because of developments in sequencing and microarray techniques. In the current review, we bring recent knowledge of the role of microRNAs in BTIC formation and therapy. Special attention is paid to two highly aggressive and well-characterized brain tumours: gliomas and medulloblastoma. As microRNA seems to be altered in the pathogenesis of many human diseases, “microRNA therapy” may now have potential to improve outcomes for brain tumour patients. In this rapidly evolving field, further understanding of miRNA biology and its contribution towards cancer can be mined for new therapeutic tools.

  20. Fibroblast Growth Factor Receptor Signaling in Oligodendrocytes Regulates Myelin Sheath Thickness

    OpenAIRE

    Furusho, M.; Dupree, J. L.; Nave, K-A; Bansal, R.

    2012-01-01

    Formation of the central nervous system (CNS) white matter is developmentally tightly regulated, but the molecules and mechanisms of myelination control in the postnatal CNS are poorly understood. Here, we show that myelin growth is controlled by Fibroblast Growth Factor (FGF) signaling, originally identified as a proliferative signal for oligodendrocyte precursor cells (OPC) in vitro. We created two lines of mice lacking both FGF-receptor 1 (Fgfr1) and Fgfr2 in oligodendrocyte lineage cells ...

  1. The orphan nuclear receptor Nr4a1 couples sympathetic and inflammatory cues in CNS-recruited macrophages to limit neuroinflammation

    OpenAIRE

    Shaked, Iftach; Hanna, Richard N.; Shaked, Helena; Chodaczek, Grzegorz; Nowyhed, Heba N.; Tweet, George; Tacke, Robert; Basat, Alp Bugra; Mikulski, Zbigniew; Togher, Susan; Miller, Jacqueline; Blatchley, Amy; Salek-Ardakani, Shahram; Darvas, Martin; Kaikkonen, Minna U.

    2015-01-01

    Molecular mechanisms linking the sympathetic stress response and inflammation remain enigmatic. Here we demonstrate that the transcription factor Nr4a1 regulates production of norepinephrine (NE) in macrophages, thereby limiting experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Lack of Nr4a1 in myeloid cells led to enhanced NE production, accelerated leukocyte infiltration to the central nervous system (CNS) and disease exacerbation in vivo. In contrast, my...

  2. Regulation of Arabidopsis Early Anther Development by Putative Cell-Cell Signaling Molecules and Transcriptional Regulators

    Institute of Scientific and Technical Information of China (English)

    Yu-Jin Sun; Carey LH Hord; Chang-Bin Chen; Hong Ma

    2007-01-01

    Anther development in flowering plants involves the formation of several cell types, including the tapetal and pollen mother cells. The use of genetic and molecular tools has led to the identification and characterization of genes that are critical for normal cell division and differentiation in Arabidopsis early anther development. We review here several recent studies on these genes, including the demonstration that the putative receptor protein kinases BAM1 and BAM2 together play essential roles in the control of early cell division and differentiation. In addition, we discuss the hypothesis that BAM1/2 may form a positive-negative feedback regulatory loop with a previously identified key regulator, SPOROCYTELESS (also called NOZZLE),to control the balance between sporogenous and somatic cell types in the anther. Furthermore, we summarize the isolation and functional analysis of the DYSFUNCTIONAL TAPETUM1 (DYT1) gene in promoting proper tapetal cell differentiation. Our finding that DYT1 encodes a putative transcription factor of the bHLH family, as well as relevant expression analyses, strongly supports a model that DYT1 serves as a critical link between upstream factors and downstream target genes that are critical for normal tapetum development and function. These studies, together with other recently published works, indicate that cell-cell communication and transcriptional control are key processes essential for cell fate specification in anther development.

  3. Common stemness regulators of embryonic and cancer stem cells

    OpenAIRE

    Hadjimichael, Christiana; Chanoumidou, Konstantina; Papadopoulou, Natalia; Arampatzi, Panagiota; Papamatheakis, Joseph; Kretsovali, Androniki

    2015-01-01

    Pluripotency of embryonic stem cells (ESCs) and induced pluripotent stem cells is regulated by a well characterized gene transcription circuitry. The circuitry is assembled by ESC specific transcription factors, signal transducing molecules and epigenetic regulators. Growing understanding of stem-like cells, albeit of more complex phenotypes, present in tumors (cancer stem cells), provides a common conceptual and research framework for basic and applied stem cell biology. In this review, we h...

  4. Role of galectin-3 in prion infections of the CNS

    International Nuclear Information System (INIS)

    Galectin-3 is a multi-functional protein and participates in mediating inflammatory reactions. The pronounced overexpression of galectin-3 in prion-infected brain tissue prompted us to study the role of this protein in a murine prion model. Immunofluorescence double-labelling identified microglia as the major cell type expressing galectin-3. Ablation of galectin-3 did not affect PrPSc-deposition and development of gliosis. However, galectin-3-/--mice showed prolonged survival times upon intracerebral and peripheral scrapie infections. Moreover, protein levels of the lysosomal activation marker LAMP-2 were markedly reduced in prion-infected galectin-3-/--mice suggesting a role of galectin-3 in regulation of lysosomal functions. Lower mRNA levels of Beclin-1 and Atg5 in prion-infected wild-type and galectin-3-/--mice indicated an impairment of autophagy although autophagosome formation was unchanged. The results point towards a detrimental role of galectin-3 in prion infections of the CNS and suggest that endo-/lysosomal dysfunction in combination with reduced autophagy may contribute to disease development

  5. Gamma-Secretase Inhibitor RO4929097 in Treating Young Patients With Relapsed or Refractory Solid Tumors, CNS Tumors, Lymphoma, or T-Cell Leukemia

    Science.gov (United States)

    2014-11-04

    Childhood Atypical Teratoid/Rhabdoid Tumor; Childhood Central Nervous System Choriocarcinoma; Childhood Central Nervous System Germinoma; Childhood Central Nervous System Mixed Germ Cell Tumor; Childhood Central Nervous System Teratoma; Childhood Central Nervous System Yolk Sac Tumor; Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Ependymoblastoma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood Infratentorial Ependymoma; Childhood Medulloepithelioma; Childhood Mixed Glioma; Childhood Oligodendroglioma; Childhood Supratentorial Ependymoma; Gonadotroph Adenoma; Pituitary Basophilic Adenoma; Pituitary Chromophobe Adenoma; Pituitary Eosinophilic Adenoma; Prolactin Secreting Adenoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Anaplastic Large Cell Lymphoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Central Nervous System Embryonal Tumor; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Grade III Lymphomatoid Granulomatosis; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Childhood Spinal Cord Neoplasm; Recurrent Childhood Subependymal Giant Cell Astrocytoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Recurrent Childhood Visual Pathway Glioma; Recurrent Pituitary Tumor; Recurrent/Refractory Childhood Hodgkin Lymphoma; T-cell Childhood Acute Lymphoblastic Leukemia; T-cell Large Granular Lymphocyte Leukemia; TSH Secreting Adenoma; Unspecified Childhood Solid Tumor, Protocol Specific

  6. Differential roles of NF-Y transcription factor in ER chaperone expression and neuronal maintenance in the CNS

    Science.gov (United States)

    Yamanaka, Tomoyuki; Tosaki, Asako; Miyazaki, Haruko; Kurosawa, Masaru; Koike, Masato; Uchiyama, Yasuo; Maity, Sankar N.; Misawa, Hidemi; Takahashi, Ryosuke; Shimogori, Tomomi; Hattori, Nobutaka; Nukina, Nobuyuki

    2016-01-01

    The mammalian central nervous system (CNS) contains various types of neurons with different neuronal functions. In contrast to established roles of cell type-specific transcription factors on neuronal specification and maintenance, whether ubiquitous transcription factors have conserved or differential neuronal function remains uncertain. Here, we revealed that inactivation of a ubiquitous factor NF-Y in different sets of neurons resulted in cell type-specific neuropathologies and gene downregulation in mouse CNS. In striatal and cerebellar neurons, NF-Y inactivation led to ubiquitin/p62 pathologies with downregulation of an endoplasmic reticulum (ER) chaperone Grp94, as we previously observed by NF-Y deletion in cortical neurons. In contrast, NF-Y inactivation in motor neurons induced neuronal loss without obvious protein deposition. Detailed analysis clarified downregulation of another ER chaperone Grp78 in addition to Grp94 in motor neurons, and knockdown of both ER chaperones in motor neurons recapitulated the pathology observed after NF-Y inactivation. Finally, additional downregulation of Grp78 in striatal neurons suppressed ubiquitin accumulation induced by NF-Y inactivation, implying that selective ER chaperone downregulation mediates different neuropathologies. Our data suggest distinct roles of NF-Y in protein homeostasis and neuronal maintenance in the CNS by differential regulation of ER chaperone expression. PMID:27687130

  7. HB-GAM (pleiotrophin) reverses inhibition of neural regeneration by the CNS extracellular matrix

    Science.gov (United States)

    Paveliev, Mikhail; Fenrich, Keith K.; Kislin, Mikhail; Kuja-Panula, Juha; Kulesskiy, Evgeny; Varjosalo, Markku; Kajander, Tommi; Mugantseva, Ekaterina; Ahonen-Bishopp, Anni; Khiroug, Leonard; Kulesskaya, Natalia; Rougon, Geneviève; Rauvala, Heikki

    2016-01-01

    Chondroitin sulfate (CS) glycosaminoglycans inhibit regeneration in the adult central nervous system (CNS). We report here that HB-GAM (heparin-binding growth-associated molecule; also known as pleiotrophin), a CS-binding protein expressed at high levels in the developing CNS, reverses the role of the CS chains in neurite growth of CNS neurons in vitro from inhibition to activation. The CS-bound HB-GAM promotes neurite growth through binding to the cell surface proteoglycan glypican-2; furthermore, HB-GAM abrogates the CS ligand binding to the inhibitory receptor PTPσ (protein tyrosine phosphatase sigma). Our in vivo studies using two-photon imaging of CNS injuries support the in vitro studies and show that HB-GAM increases dendrite regeneration in the adult cerebral cortex and axonal regeneration in the adult spinal cord. Our findings may enable the development of novel therapies for CNS injuries. PMID:27671118

  8. Single-Cell Genomics Unveils Critical Regulators of Th17 Cell Pathogenicity.

    Science.gov (United States)

    Gaublomme, Jellert T; Yosef, Nir; Lee, Youjin; Gertner, Rona S; Yang, Li V; Wu, Chuan; Pandolfi, Pier Paolo; Mak, Tak; Satija, Rahul; Shalek, Alex K; Kuchroo, Vijay K; Park, Hongkun; Regev, Aviv

    2015-12-01

    Extensive cellular heterogeneity exists within specific immune-cell subtypes classified as a single lineage, but its molecular underpinnings are rarely characterized at a genomic scale. Here, we use single-cell RNA-seq to investigate the molecular mechanisms governing heterogeneity and pathogenicity of Th17 cells isolated from the central nervous system (CNS) and lymph nodes (LN) at the peak of autoimmune encephalomyelitis (EAE) or differentiated in vitro under either pathogenic or non-pathogenic polarization conditions. Computational analysis relates a spectrum of cellular states in vivo to in-vitro-differentiated Th17 cells and unveils genes governing pathogenicity and disease susceptibility. Using knockout mice, we validate four new genes: Gpr65, Plzp, Toso, and Cd5l (in a companion paper). Cellular heterogeneity thus informs Th17 function in autoimmunity and can identify targets for selective suppression of pathogenic Th17 cells while potentially sparing non-pathogenic tissue-protective ones. PMID:26607794

  9. CNS disease triggering Takotsubo stress cardiomyopathy.

    Science.gov (United States)

    Finsterer, Josef; Wahbi, Karim

    2014-12-15

    There are a number of hereditary and non-hereditary central nervous system (CNS) disorders, which directly or indirectly affect the heart (brain-heart disorders). The most well-known of these CNS disorders are epilepsy, stroke, infectious or immunological encephalitis/meningitis, migraine, and traumatic brain injury. In addition, a number of hereditary and non-hereditary neurodegenerative disorders may impair cardiac functions. Affection of the heart may manifest not only as arrhythmias, myocardial infarction, autonomic impairment, systolic dysfunction/heart failure, arterial hypertension, or pulmonary hypertension, but also as stress cardiomyopathy (Takotsubo syndrome, TTS). CNS disease triggering TTS includes subarachnoid bleeding, epilepsy, ischemic stroke, intracerebral bleeding, migraine, encephalitis, traumatic brain injury, PRES syndrome, or ALS. Usually, TTS is acutely precipitated by stress triggered by various different events. TTS is one of the cardiac abnormalities most frequently induced by CNS disorders. Appropriate management of TTS from CNS disorders is essential to improve the outcome of affected patients. PMID:25213573

  10. PEG minocycline-liposomes ameliorate CNS autoimmune disease.

    Directory of Open Access Journals (Sweden)

    Wei Hu

    Full Text Available BACKGROUND: Minocycline is an oral tetracycline derivative with good bioavailability in the central nervous system (CNS. Minocycline, a potent inhibitor of matrix metalloproteinase (MMP-9, attenuates disease activity in experimental autoimmune encephalomyelitis (EAE, an animal model of multiple sclerosis (MS. Potential adverse effects associated with long-term daily minocycline therapy in human patients are concerning. Here, we investigated whether less frequent treatment with long-circulating polyethylene glycol (PEG minocycline liposomes are effective in treating EAE. FINDINGS: Performing in vitro time kinetic studies of PEG minocycline-liposomes in human peripheral blood mononuclear cells (PBMCs, we determined that PEG minocycline-liposome preparations stabilized with CaCl(2 are effective in diminishing MMP-9 activity. Intravenous injections of PEG minocycline-liposomes every five days were as effective in ameliorating clinical EAE as daily intraperitoneal injections of minocycline. Treatment of animals with PEG minocycline-liposomes significantly reduced the number of CNS-infiltrating leukocytes, and the overall expression of MMP-9 in the CNS. There was also a significant suppression of MMP-9 expression and proteolytic activity in splenocytes of treated animals, but not in CNS-infiltrating leukocytes. Thus, leukocytes gaining access to the brain and spinal cord require the same absolute amount of MMP-9 in all treatment groups, but minocycline decreases the absolute cell number. CONCLUSIONS: Our data indicate that less frequent injections of PEG minocycline-liposomes are an effective alternative pharmacotherapy to daily minocycline injections for the treatment of CNS autoimmune diseases. Also, inhibition of MMP-9 remains a promising treatment target in EAE and patients with MS.

  11. CD8+ T cells in inflammatory demyelinating disease

    DEFF Research Database (Denmark)

    Weiss, Hanne A; Millward, Jason M; Owens, Trevor

    2007-01-01

    We review the contribution made by CD8+ T cells to inflammation in the central nervous system (CNS) in Multiple Sclerosis (MS), and discuss their role in the animal model Experimental Autoimmune Encephalomyelitis (EAE). We show that the inflammatory cytokines interferon-gamma and interleukin-17...... are differentially regulated in CNS-infiltrating CD4+ and CD8+ T cells in EAE, and that CD8+ T cells regulate disease. In MS, CD8+ T cells appear to play a role in promotion of disease, so cytokine regulation is likely different in CD8+ T cells in MS and EAE...

  12. Safety Evaluation of CNS Administered Biologics-Study Design, Data Interpretation, and Translation to the Clinic.

    Science.gov (United States)

    Vuillemenot, Brian R; Korte, Sven; Wright, Teresa L; Adams, Eric L; Boyd, Robert B; Butt, Mark T

    2016-07-01

    Many central nervous system (CNS) diseases are inadequately treated by systemically administered therapies due to the blood brain barrier (BBB), which prevents achieving adequate drug concentrations at sites of action. Due to the increasing prevalence of neurodegenerative diseases and the inability of most systemically administered therapies to cross the BBB, direct CNS delivery will likely play an increasing role in treatment. Administration of large molecules, cells, viral vectors, oligonucleotides, and other novel therapies directly to the CNS via the subarachnoid space, ventricular system, or parenchyma overcomes this obstacle. Clinical experience with direct CNS administration of small molecule therapies suggests that this approach may be efficacious for the treatment of neurodegenerative disorders using biological therapies. Risks of administration into the brain tissue or cerebrospinal fluid include local damage from implantation of the delivery system and/or administration of the therapeutic and reactions affecting the CNS. Preclinical safety studies on CNS administered compounds must differentiate between the effects of the test article, the delivery device, and/or the vehicle, and assess exacerbations of reactions due to combinations of effects. Animal models characterized for safety assessment of CNS administered therapeutics have enabled human trials, but interpretation can be challenging. This manuscript outlines the challenges of preclinical intrathecal/intracerebroventricular/intraparenchymal studies, evaluation of results, considerations for special endpoints, and translation of preclinical findings to enable first-in-human trials. Recommendations will be made based on the authors' collective experience with conducting these studies to enable clinical development of CNS-administered biologics. PMID:27354708

  13. Impact of dual expression of MYC and BCL2 by immunohistochemistry on the risk of CNS relapse in DLBCL.

    Science.gov (United States)

    Savage, Kerry J; Slack, Graham W; Mottok, Anja; Sehn, Laurie H; Villa, Diego; Kansara, Roopesh; Kridel, Robert; Steidl, Christian; Ennishi, Daisuke; Tan, King L; Ben-Neriah, Susana; Johnson, Nathalie A; Connors, Joseph M; Farinha, Pedro; Scott, David W; Gascoyne, Randy D

    2016-05-01

    Dual expression of MYC and BCL2 by immunohistochemistry (IHC) is associated with poor outcome in diffuse large B-cell lymphoma (DLBCL). Dual translocation of MYC and BCL2, so-called "double-hit lymphoma," has been associated with a high risk of central nervous system (CNS) relapse; however, the impact of dual expression of MYC and BCL2 (dual expressers) on the risk of CNS relapse remains unknown. Pretreatment formalin-fixed paraffin-embedded DLBCL biopsies derived from patients subsequently treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) were assembled on tissue microarrays from 2 studies and were evaluated for expression of MYC and BCL2 by IHC. In addition, cell of origin was determined by IHC and the Lymph2Cx gene expression assay in a subset of patients. We identified 428 patients who met the inclusion criteria. By the recently described CNS risk score (CNS-International Prognostic Index [CNS-IPI]), 34% were low risk (0 to 1), 45% were intermediate risk (2 to 3), and 21% were high risk (4 or greater). With a median follow-up of 6.8 years, the risk of CNS relapse was higher in dual expressers compared with non-dual expressers (2-year risk, 9.7% vs 2.2%; P = .001). Patients with activated B-cell or non-germinal center B-cell type DLBCL also had an increased risk of CNS relapse. However, in multivariate analysis, only dual expresser status and CNS-IPI were associated with CNS relapse. Dual expresser MYC(+) BCL2(+) DLBCL defines a group at high risk of CNS relapse, independent of CNS-IPI score and cell of origin. Dual expresser status may help to identify a high-risk group who should undergo CNS-directed evaluation and consideration of prophylactic strategies. PMID:26834242

  14. Auto Transplant for High Risk or Relapsed Solid or CNS Tumors

    Science.gov (United States)

    2016-01-22

    Ewing's Family Tumors; Renal Tumors; Hepatoblastoma; Rhabdomyosarcoma; Soft Tissue Sarcoma; Primary Malignant Brain Neoplasms; Retinoblastoma; Medulloblastoma; Supra-tentorial Primative Neuro-Ectodermal Tumor (PNET); Atypical Teratoid/Rhabdoid Tumor (AT/RT); CNS Tumors; Germ Cell Tumors

  15. Non-human primate models of SIV infection and CNS neuropathology.

    Science.gov (United States)

    Williams, Kenneth; Lackner, Andrew; Mallard, Jaclyn

    2016-08-01

    Non-human primate models of AIDS and neuroAIDS are the premiere model of HIV infection of the CNS and neuropathogenesis. This review discusses current SIV infection models of neuroAIDS emphasizing findings in the last two years. Consistent in these findings is the interplay between host factors that regulate immune responses to virus and viral replication. Several rapid models of AIDS with consistent CNS pathogenesis exist, each of which modulates by antibody treatment or viruses that cause rapid immune suppression and replicate well in macrophages. Consistent in all of these models are data underscoring the importance of monocyte and macrophage activation, infection and accumulation in the CNS. PMID:27544476

  16. Cellular Pressure and Volume Regulation and Implications for Cell Mechanics

    OpenAIRE

    Jiang, Hongyuan; Sun, Sean X.

    2013-01-01

    In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death, and migration. Volume and shape regulation also directly impacts the mechanics of cells and tissues. Here, we develop a mathematical model of cellular volume and pressure regulation, incorporating essential elements such as water permeation, mechanosensitive channels, active ion pumps, and active stresses in the cortex. The model can fully explain recent experimental data, and it pr...

  17. Observations at the CNS-PNS border of ventral roots connected to a neuroma

    Directory of Open Access Journals (Sweden)

    Sten Remahl

    2010-10-01

    Full Text Available Previous studies have shown that numerous sprouts originating from a neuroma, after nerve injury in neonatal animals, can invade spinal nerve roots. In this study the border between the central and peripheral nervous system (CNS-PNS border of ventral roots in kittens was examined with both light and electron microscopy after early postnatal sciatic nerve resection. A transient ingrowth of substance P positive axons was observed into the CNS, but no spouts remained 6 weeks after the injury. Using serial sections and electron microscopy it was possible to identify small bundles of unmyelinated axons that penetrated from the root fascicles for a short distance into the CNS. These axons ended blindly, sometimes with a growth cone-like terminal swelling filled with vesicles. The axon bundles were accompanied by p75 positive cells in both the root fascicles and the pia mater, but not in the CNS. It may thus be suggested that neurotrophin presenting p75 positive cells could facilitate axonal growth into the pia mater and that the lack of such cells in the CNS compartment might contribute to the failure of growth into the CNS. A maldevelopment of myelin sheaths at the CNS-PNS border of motor axons was observed and it seems possible that this could have consequences for the propagation of action potential across this region after neonatal nerve injury.

  18. Chondroitin sulphate proteoglycans: extracellular matrix proteins that regulate immunity of the central nervous system.

    Science.gov (United States)

    Haylock-Jacobs, Sarah; Keough, Michael B; Lau, Lorraine; Yong, V Wee

    2011-10-01

    The extracellular matrix (ECM) is a complex network of scaffolding molecules that also plays an important role in cell signalling, migration and tissue structure. In the central nervous system (CNS), the ECM is integral to the efficient development/guidance and survival of neurons and axons. However, changes in distribution of the ECM in the CNS may significantly enhance pathology in CNS disease or following injury. One group of ECM proteins that is important for CNS homeostasis is the chondroitin sulphate proteoglycans (CSPGs). Up-regulation of these molecules has been demonstrated to be both desirable and detrimental following CNS injury. Taking cues from arthritis, where there is a strong anti-CSPG immune response, there is evidence that suggests that CSPGs may influence immunity during CNS pathological conditions. This review focuses on the role of CSPGs in CNS pathologies as well as in immunity, both from a viewpoint of how they may inhibit repair and exacerbate damage in the CNS, and how they are involved in activation and function of peripheral immune cells, particularly in multiple sclerosis. Lastly, we address how CSPGs may be manipulated to improve disease outcomes.

  19. Regulation of Water in Plant Cells

    Science.gov (United States)

    Kowles, Richard V.

    2010-01-01

    Cell water relationships are important topics to be included in cell biology courses. Differences exist in the control of water relationships in plant cells relative to control in animal cells. One important reason for these differences is that turgor pressure is a consideration in plant cells. Diffusion and osmosis are the underlying factors…

  20. Role of autophagy in the regulation of epithelial cell junctions.

    Science.gov (United States)

    Nighot, Prashant; Ma, Thomas

    2016-01-01

    Autophagy is a cell survival mechanism by which bulk cytoplasmic material, including soluble macromolecules and organelles, is targeted for lysosomal degradation. The role of autophagy in diverse cellular processes such as metabolic stress, neurodegeneration, cancer, aging, immunity, and inflammatory diseases is being increasingly recognized. Epithelial cell junctions play an integral role in the cell homeostasis via physical binding, regulating paracellular pathways, integrating extracellular cues into intracellular signaling, and cell-cell communication. Recent data indicates that cell junction composition is very dynamic. The junctional protein complexes are actively regulated in response to various intra- and extra-cellular clues by intracellular trafficking and degradation pathways. This review discusses the recent and emerging information on how autophagy regulates various epithelial cell junctions. The knowledge of autophagy regulation of epithelial junctions will provide further rationale for targeting autophagy in a wide variety of human disease conditions. PMID:27583189

  1. Gangliosides in cell recognition and membrane protein regulation

    OpenAIRE

    Lopez, Pablo H. H.; Schnaar, Ronald L.

    2009-01-01

    Gangliosides, sialic acid-bearing glycosphingolipids, are expressed on all vertebrate cells, and are the major glycans on nerve cells. They are anchored to the plasma membrane through their ceramide lipids with their varied glycans extending into the extracellular space. Through sugar-specific interactions with glycan binding proteins on apposing cells, gangliosides function as receptors in cell-cell recognition, regulating natural killer cell cytotoxicity via Siglec-7 binding, myelin-axon in...

  2. Clitoria ternatea and the CNS.

    Science.gov (United States)

    Jain, Neeti N; Ohal, C C; Shroff, S K; Bhutada, R H; Somani, R S; Kasture, V S; Kasture, S B

    2003-06-01

    The present investigation was aimed at determining the spectrum of activity of the methanolic extract of Clitoria ternatea (CT) on the CNS. The CT was studied for its effect on cognitive behavior, anxiety, depression, stress and convulsions induced by pentylenetetrazol (PTZ) and maximum electroshock (MES). To explain these effects, the effect of CT was also studied on behavior mediated by dopamine (DA), noradrenaline, serotonin and acetylcholine. The extract decreased time required to occupy the central platform (transfer latency, TL) in the elevated plus maze (EPM) and increased discrimination index in the object recognition test, indicating nootropic activity. The extract was more active in the object recognition test than in the EPM. The extract increased occupancy in the open arm of EPM by 160% and in the lit box of the light/dark exploration test by 157%, indicating its anxiolytic activity. It decreased the duration of immobility in tail suspension test (suggesting its antidepressant activity), reduced stress-induced ulcers and reduced the convulsing action of PTZ and MES. The extract exhibited tendency to reduce the intensity of behavior mediated via serotonin and acetylcholine. The effect on DA- and noradrenaline-mediated behavior was not significant. In conclusion, the extract was found to possess nootropic, anxiolytic, antidepressant, anticonvulsant and antistress activity. Further studies are necessary to isolate the active principle responsible for the activities and to understand its mode of action. PMID:12895670

  3. Tetracycline regulator expression alters the transcriptional program of mammalian cells

    OpenAIRE

    Hackl, Hubert; Rommer, Anna; Konrad, Torsten A; Nassimbeni, Christine; Wieser, Rotraud

    2010-01-01

    Tetracycline regulated ectopic gene expression is a widely used tool to study gene function. However, the tetracycline regulator (tetR) itself has been reported to cause certain phenotypic changes in mammalian cells. We, therefore, asked whether human myeloid U937 cells expressing the tetR in an autoregulated manner would exhibit alterations in gene expression upon removal of tetracycline.

  4. Coordinated regulation of myeloid cells by tumours.

    Science.gov (United States)

    Gabrilovich, Dmitry I; Ostrand-Rosenberg, Suzanne; Bronte, Vincenzo

    2012-03-22

    Myeloid cells are the most abundant nucleated haematopoietic cells in the human body and are a collection of distinct cell populations with many diverse functions. The three groups of terminally differentiated myeloid cells - macrophages, dendritic cells and granulocytes - are essential for the normal function of both the innate and adaptive immune systems. Mounting evidence indicates that the tumour microenvironment alters myeloid cells and can convert them into potent immunosuppressive cells. Here, we consider myeloid cells as an intricately connected, complex, single system and we focus on how tumours manipulate the myeloid system to evade the host immune response.

  5. In vivo dynamics of innate immune sentinels in the CNS

    OpenAIRE

    Nayak, Debasis; Zinselmeyer, Bernd H.; Corps, Kara N.; McGavern, Dorian B.

    2012-01-01

    The innate immune system is comprised of cellular sentinels that often serve as the first responders to injury and invading pathogens. Our basic understanding of innate immunity is derived from research conducted in peripheral lymphoid tissues. However, it is now recognized that most non-lymphoid tissues throughout the body are equipped with specialized innate immune cells that are uniquely adapted to the niches in which they reside. The central nervous system (CNS) is a particularly interest...

  6. Genetic regulation of programmed cell death in Drosophila

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Programmed cell death plays an important role in maintaining homeostasis during animal development, and has been conserved in animals as different as nematodes and humans. Recent studies of Drosophila have provided valuable information toward our understanding of genetic regulation of death. Different signals trigger the novel death regulators rpr, hid, and grim, that utilize the evolutionarily conserved iap and ark genes to modulate caspase function. Subsequent removal of dying cells also appears to be accomplished by conserved mechanisms. The similarity between Drosophila and human in cell death signaling pathways illustrate the promise of fruit flies as a model system to elucidate the mechanisms underlying regulation of programmed cell death.

  7. Observations at the CNS-PNS Border of Ventral Roots Connected to a Neuroma.

    Science.gov (United States)

    Remahl, Sten; Angeria, Maria; Remahl, Ingela Nilsson; Carlstedt, Thomas; Risling, Mårten

    2010-01-01

    Previous studies have shown that numerous sprouts originating from a neuroma, after nerve injury in neonatal animals, can invade spinal nerve roots. However, no study with a focus on how such sprouts behave when they reach the border between the central and peripheral nervous system (CNS-PNS border) has been published. In this study we have in detail examined the CNS-PNS border of ventral roots in kittens with light and electron microscopy after early postnatal sciatic nerve resection. A transient ingrowth of substance P positive axons was observed into the CNS, but no spouts remained 6 weeks after the injury. Using serial sections and electron microscopy it was possible to identify small bundles of unmyelinated axons that penetrated from the root fascicles for a short distance into the CNS. These axons ended blindly, sometimes with a growth cone-like terminal swelling filled with vesicles. The axon bundles were accompanied by p75 positive cells in both the root fascicles and the pia mater, but not in the CNS. It may thus be suggested that neurotrophin presenting p75 positive cells could facilitate axonal growth into the pia mater and that the lack of such cells in the CNS compartment might contribute to the failure of growth into the CNS. A maldevelopment of myelin sheaths at the CNS-PNS border of motor axons was observed and it seems possible that this could have consequences for the propagation of action potential across this region after neonatal nerve injury. Thus, in this first detailed study on the behavior of recurrent sprouts at the CNS-PNS border.

  8. Slit/Robo1 signaling regulates neural tube development by balancing neuroepithelial cell proliferation and differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guang; Li, Yan; Wang, Xiao-yu [Key Laboratory for Regenerative Medicine of The Ministry of Education, Department of Histology and Embryology, School of Medicine, Jinan University, Guangzhou 510632 (China); Han, Zhe [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510224 (China); Chuai, Manli [College of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH (United Kingdom); Wang, Li-jing [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510224 (China); Ho Lee, Kenneth Ka [Stem Cell and Regeneration Thematic Research Programme, School of Biomedical Sciences, Chinese University of Hong Kong, Shatin (Hong Kong); Geng, Jian-guo, E-mail: jgeng@umich.edu [Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University, Guangzhou 510224 (China); Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI 48109 (United States); Yang, Xuesong, E-mail: yang_xuesong@126.com [Key Laboratory for Regenerative Medicine of The Ministry of Education, Department of Histology and Embryology, School of Medicine, Jinan University, Guangzhou 510632 (China)

    2013-05-01

    Formation of the neural tube is the morphological hallmark for development of the embryonic central nervous system (CNS). Therefore, neural tube development is a crucial step in the neurulation process. Slit/Robo signaling was initially identified as a chemo-repellent that regulated axon growth cone elongation, but its role in controlling neural tube development is currently unknown. To address this issue, we investigated Slit/Robo1 signaling in the development of chick neCollege of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH, UKural tube and transgenic mice over-expressing Slit2. We disrupted Slit/Robo1 signaling by injecting R5 monoclonal antibodies into HH10 neural tubes to block the Robo1 receptor. This inhibited the normal development of the ventral body curvature and caused the spinal cord to curl up into a S-shape. Next, Slit/Robo1 signaling on one half-side of the chick embryo neural tube was disturbed by electroporation in ovo. We found that the morphology of the neural tube was dramatically abnormal after we interfered with Slit/Robo1 signaling. Furthermore, we established that silencing Robo1 inhibited cell proliferation while over-expressing Robo1 enhanced cell proliferation. We also investigated the effects of altering Slit/Robo1 expression on Sonic Hedgehog (Shh) and Pax7 expression in the developing neural tube. We demonstrated that over-expressing Robo1 down-regulated Shh expression in the ventral neural tube and resulted in the production of fewer HNK-1{sup +} migrating neural crest cells (NCCs). In addition, Robo1 over-expression enhanced Pax7 expression in the dorsal neural tube and increased the number of Slug{sup +} pre-migratory NCCs. Conversely, silencing Robo1 expression resulted in an enhanced Shh expression and more HNK-1{sup +} migrating NCCs but reduced Pax7 expression and fewer Slug{sup +} pre-migratory NCCs were observed. In conclusion, we propose that Slit/Robo1 signaling is involved in regulating neural tube

  9. Slit/Robo1 signaling regulates neural tube development by balancing neuroepithelial cell proliferation and differentiation

    International Nuclear Information System (INIS)

    Formation of the neural tube is the morphological hallmark for development of the embryonic central nervous system (CNS). Therefore, neural tube development is a crucial step in the neurulation process. Slit/Robo signaling was initially identified as a chemo-repellent that regulated axon growth cone elongation, but its role in controlling neural tube development is currently unknown. To address this issue, we investigated Slit/Robo1 signaling in the development of chick neCollege of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH, UKural tube and transgenic mice over-expressing Slit2. We disrupted Slit/Robo1 signaling by injecting R5 monoclonal antibodies into HH10 neural tubes to block the Robo1 receptor. This inhibited the normal development of the ventral body curvature and caused the spinal cord to curl up into a S-shape. Next, Slit/Robo1 signaling on one half-side of the chick embryo neural tube was disturbed by electroporation in ovo. We found that the morphology of the neural tube was dramatically abnormal after we interfered with Slit/Robo1 signaling. Furthermore, we established that silencing Robo1 inhibited cell proliferation while over-expressing Robo1 enhanced cell proliferation. We also investigated the effects of altering Slit/Robo1 expression on Sonic Hedgehog (Shh) and Pax7 expression in the developing neural tube. We demonstrated that over-expressing Robo1 down-regulated Shh expression in the ventral neural tube and resulted in the production of fewer HNK-1+ migrating neural crest cells (NCCs). In addition, Robo1 over-expression enhanced Pax7 expression in the dorsal neural tube and increased the number of Slug+ pre-migratory NCCs. Conversely, silencing Robo1 expression resulted in an enhanced Shh expression and more HNK-1+ migrating NCCs but reduced Pax7 expression and fewer Slug+ pre-migratory NCCs were observed. In conclusion, we propose that Slit/Robo1 signaling is involved in regulating neural tube development by tightly

  10. Microphthalmia transcription factor regulates pancreatic β-cell function.

    Science.gov (United States)

    Mazur, Magdalena A; Winkler, Marcus; Ganic, Elvira; Colberg, Jesper K; Johansson, Jenny K; Bennet, Hedvig; Fex, Malin; Nuber, Ulrike A; Artner, Isabella

    2013-08-01

    Precise regulation of β-cell function is crucial for maintaining blood glucose homeostasis. Pax6 is an essential regulator of β-cell-specific factors like insulin and Glut2. Studies in the developing eye suggest that Pax6 interacts with Mitf to regulate pigment cell differentiation. Here, we show that Mitf, like Pax6, is expressed in all pancreatic endocrine cells during mouse postnatal development and in the adult islet. A Mitf loss-of-function mutation results in improved glucose tolerance and enhanced insulin secretion but no increase in β-cell mass in adult mice. Mutant β-cells secrete more insulin in response to glucose than wild-type cells, suggesting that Mitf is involved in regulating β-cell function. In fact, the transcription of genes critical for maintaining glucose homeostasis (insulin and Glut2) and β-cell formation and function (Pax4 and Pax6) is significantly upregulated in Mitf mutant islets. The increased Pax6 expression may cause the improved β-cell function observed in Mitf mutant animals, as it activates insulin and Glut2 transcription. Chromatin immunoprecipitation analysis shows that Mitf binds to Pax4 and Pax6 regulatory regions, suggesting that Mitf represses their transcription in wild-type β-cells. We demonstrate that Mitf directly regulates Pax6 transcription and controls β-cell function. PMID:23610061

  11. Regulation of satellite cell function in sarcopenia

    OpenAIRE

    Alway, Stephen E.; Myers, Matthew J.; Mohamed, Junaith S.

    2014-01-01

    The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell) function that is impacted by the environment (niche) of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse or rehabilitation in sarcopenic muscles. Nutritional intervention provides...

  12. Regulation of Satellite Cell Function in Sarcopenia

    OpenAIRE

    Alway, Stephen E.; Myers, Matthew J.; Mohamed, Junaith S.

    2014-01-01

    The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell) function that is impacted by the environment (niche) of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse, or rehabilitation in sarcopenic muscles. Nutritional intervention provide...

  13. Cellular pressure and volume regulation and implications for cell mechanics.

    Science.gov (United States)

    Jiang, Hongyuan; Sun, Sean X

    2013-08-01

    In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death, and migration. Volume and shape regulation also directly impacts the mechanics of cells and tissues. Here, we develop a mathematical model of cellular volume and pressure regulation, incorporating essential elements such as water permeation, mechanosensitive channels, active ion pumps, and active stresses in the cortex. The model can fully explain recent experimental data, and it predicts cellular volume and pressure for several models of cell cortical mechanics. Moreover, we show that when cells are subjected to an externally applied load, such as in an atomic force microscopy indentation experiment, active regulation of volume and pressure leads to a complex cellular response. Instead of the passive mechanics of the cortex, the observed cell stiffness depends on several factors working together. This provides a mathematical explanation of rate-dependent response of cells under force. PMID:23931309

  14. Complement regulator CD46 temporally regulates cytokine production by conventional and unconventional T cells

    OpenAIRE

    Kemper, Claudia; Cardone, John; Le Friec, Gaelle; Vantourout, Pierre; Roberts, Andrew; Fuchs, Anja; Jackson, Ian; Suddason, Tesha; Lord, Graham; Atkinson, John Petterson; Cope, Andrew; Hayday, Adrian C.

    2010-01-01

    Abstract This study reveals a novel form of immunoregulation: engagement on CD4+ T cells of the complement regulator CD46 promotes TH1 effector potential, but as interleukin-2 (IL-2) accumulates, "switches" cells toward a regulatory phenotype, attenuating IL-2 production via the transcriptional regulator ICER/CREM, and upregulating IL-10 following interaction of the CD46-tail with SPAKinase. Activated CD4+ T cells produce CD46 ligands, and blocking CD46 inhibits IL-10 production. F...

  15. Expression profiling of genes regulated by TGF-beta: Differential regulation in normal and tumour cells

    Directory of Open Access Journals (Sweden)

    Takahashi Takashi

    2007-04-01

    Full Text Available Abstract Background TGF-beta is one of the key cytokines implicated in various disease processes including cancer. TGF-beta inhibits growth and promotes apoptosis in normal epithelial cells and in contrast, acts as a pro-tumour cytokine by promoting tumour angiogenesis, immune-escape and metastasis. It is not clear if various actions of TGF-beta on normal and tumour cells are due to differential gene regulations. Hence we studied the regulation of gene expression by TGF-beta in normal and cancer cells. Results Using human 19 K cDNA microarrays, we show that 1757 genes are exclusively regulated by TGF-beta in A549 cells in contrast to 733 genes exclusively regulated in HPL1D cells. In addition, 267 genes are commonly regulated in both the cell-lines. Semi-quantitative and real-time qRT-PCR analysis of some genes agrees with the microarray data. In order to identify the signalling pathways that influence TGF-beta mediated gene regulation, we used specific inhibitors of p38 MAP kinase, ERK kinase, JNK kinase and integrin signalling pathways. The data suggest that regulation of majority of the selected genes is dependent on at least one of these pathways and this dependence is cell-type specific. Interestingly, an integrin pathway inhibitor, RGD peptide, significantly affected TGF-beta regulation of Thrombospondin 1 in A549 cells. Conclusion These data suggest major differences with respect to TGF-beta mediated gene regulation in normal and transformed cells and significant role of non-canonical TGF-beta pathways in the regulation of many genes by TGF-beta.

  16. Regulation of Stem Cell Differentiation by Histone Methyltransferases and Demethylases

    DEFF Research Database (Denmark)

    Pasini, D; Bracken, A P; Agger, K;

    2008-01-01

    The generation of different cell types from stem cells containing identical genetic information and their organization into tissues and organs during development is a highly complex process that requires defined transcriptional programs. Maintenance of such programs is epigenetically regulated...... and the factors involved in these processes are often essential for development. The activities required for cell-fate decisions are frequently deregulated in human tumors, and the elucidation of the molecular mechanisms that regulate these processes is therefore important for understanding both developmental...

  17. Contactin-1 regulates myelination and nodal/paranodal domain organization in the central nervous system

    OpenAIRE

    Çolakoğlu, Gülsen; Bergstrom-Tyrberg, Ulrika; Berglund, Erik O.; Ranscht, Barbara

    2014-01-01

    Myelin is a multilayered membrane sheath that encircles axons to enable rapid information processing and protect neurons. Formation of myelin requires communication between axons and oligodendrocytes, the myelin-forming cells in the CNS. Here we identify Contactin-1 as a critical signal for axon–glia communication in CNS myelin. Gene ablation in mice shows that Contactin-1 is necessary for myelin sheath formation by oligodendrocytes and establishment of paranodal axoglial junctions that regul...

  18. Creatine kinase in cell cycle regulation and cancer.

    Science.gov (United States)

    Yan, Yong-Bin

    2016-08-01

    The phosphocreatine-creatine kinase (CK) shuttle system is increasingly recognized as a fundamental mechanism for ATP homeostasis in both excitable and non-excitable cells. Many intracellular processes are ATP dependent. Cell division is a process requiring a rapid rate of energy turnover. Cell cycle regulation is also a key point to understanding the mechanisms underlying cancer progression. It has been known for about 40 years that aberrant CK levels are associated with various cancers and for over 30 years that CK is involved in mitosis regulation. However, the underlying molecular mechanisms have not been investigated sufficiently until recently. By maintaining ATP at sites of high-energy demand, CK can regulate cell cycle progression by affecting the intracellular energy status as well as by influencing signaling pathways that are essential to activate cell division and cytoskeleton reorganization. Aberrant CK levels may impair cell viability under normal or stressed conditions and induce cell death. The involvement of CK in cell cycle regulation and cellular energy metabolism makes it a potential diagnostic biomarker and therapeutic target in cancer. To understand the multiple physiological/pathological functions of CK, it is necessary to identify CK-binding partners and regulators including proteins, non-coding RNAs and participating endogenous small molecular weight chemical compounds. This review will focus on molecular mechanisms of CK in cell cycle regulation and cancer progression. It will also discuss the implications of recent mechanistic studies, the emerging problems and future challenges of the multifunctional enzyme CK. PMID:27020776

  19. Oncogenic KRAS Regulates Tumor Cell Signaling via Stromal Reciprocation.

    Science.gov (United States)

    Tape, Christopher J; Ling, Stephanie; Dimitriadi, Maria; McMahon, Kelly M; Worboys, Jonathan D; Leong, Hui Sun; Norrie, Ida C; Miller, Crispin J; Poulogiannis, George; Lauffenburger, Douglas A; Jørgensen, Claus

    2016-05-01

    Oncogenic mutations regulate signaling within both tumor cells and adjacent stromal cells. Here, we show that oncogenic KRAS (KRAS(G12D)) also regulates tumor cell signaling via stromal cells. By combining cell-specific proteome labeling with multivariate phosphoproteomics, we analyzed heterocellular KRAS(G12D) signaling in pancreatic ductal adenocarcinoma (PDA) cells. Tumor cell KRAS(G12D) engages heterotypic fibroblasts, which subsequently instigate reciprocal signaling in the tumor cells. Reciprocal signaling employs additional kinases and doubles the number of regulated signaling nodes from cell-autonomous KRAS(G12D). Consequently, reciprocal KRAS(G12D) produces a tumor cell phosphoproteome and total proteome that is distinct from cell-autonomous KRAS(G12D) alone. Reciprocal signaling regulates tumor cell proliferation and apoptosis and increases mitochondrial capacity via an IGF1R/AXL-AKT axis. These results demonstrate that oncogene signaling should be viewed as a heterocellular process and that our existing cell-autonomous perspective underrepresents the extent of oncogene signaling in cancer. VIDEO ABSTRACT. PMID:27087446

  20. INS/CNS/GNSS integrated navigation technology

    CERN Document Server

    Quan, Wei; Gong, Xiaolin; Fang, Jiancheng

    2015-01-01

    This book not only introduces the principles of INS, CNS and GNSS, the related filters and semi-physical simulation, but also systematically discusses the key technologies needed for integrated navigations of INS/GNSS, INS/CNS, and INS/CNS/GNSS, respectively. INS/CNS/GNSS integrated navigation technology has established itself as an effective tool for precise positioning navigation, which can make full use of the complementary characteristics of different navigation sub-systems and greatly improve the accuracy and reliability of the integrated navigation system. The book offers a valuable reference guide for graduate students, engineers and researchers in the fields of navigation and its control. Dr. Wei Quan, Dr. Jianli Li, Dr. Xiaolin Gong and Dr. Jiancheng Fang are all researchers at the Beijing University of Aeronautics and Astronautics.

  1. Regulation of Natural Killer Cell Function by STAT3

    Directory of Open Access Journals (Sweden)

    Nicholas eCacalano

    2016-04-01

    Full Text Available Natural killer (NK cells, key members of a distinct hempatopoietic lineage, innate lymphoid cells (ILCs, are critical effectors that mediate cytotoxicity toward tumor and virally-infected cells but also regulate inflammation, antigen presentation and the adaptive immune response. It has been shown that NK cells can regulate the development and activation of many other components of the immune response such as dendritic cells, which in turn, modulate the function of NK cells in multiple synergistic feed back loops driven by cell-cell contact and the secretion of cytokines and chemokines that control effector function and migration of cells to sites of immune activation. The Signal Transducer and Activator of Transcription (STAT-3 is involved in driving almost all of the pathways that control NK cytolytic activity as well as the reciprocal regulatory interactions between NK cells and other components of the immune system. In the context of tumor immunology, NK cells are a first line of defense that eliminates pre-cancerous and transformed cells early in the process of carcinogenesis, through a mechanism of immune surveillance. Even after tumors become established, NK cells are critical components of anti-cancer immunity: dysfunctional NK cells are often found in the peripheral blood of cancer patients and the lack of NK cells in the tumor microenvironment often correlates with poor prognosis. The pathways and soluble factors activated in tumor-associated NK cells, cancer cells, and regulatory myeloid cells which determine the outcome of cancer immunity are all critically regulated by STAT3. Using the tumor microenvironment as a paradigm, we present here an overview of the research that has revealed fundamental mechanisms through which STAT3 regulates all aspects of natural killer cell biology, including NK development, activation, target cell killing, and fine tuning of the innate and adaptive immune responses.

  2. Regulation of cell death in cancer - possible implications for immunotherapy

    OpenAIRE

    Simone eFulda

    2013-01-01

    Since most anticancer therapies including immunotherapy trigger programmed cell death in cancer cells, defective cell death programs can lead to treatment resistance and tumor immune escape. Therefore, evasion of programmed cell death may provide one possible explanation as to why cancer immunotherapy has so far only shown modest clinical benefits for children with cancer. A better understanding of the molecular mechanisms that regulate sensitivity and resistance to programmed cell death is e...

  3. Telomere regulation in pluripotent stem cells

    OpenAIRE

    Huang, Yan; Liang, Puping; Liu, Dan; Huang, Junjiu; Songyang, Zhou

    2014-01-01

    Pluripotent stem cells (PSCs) have the potential to produce any types of cells from all three basic germ layers and the capacity to self-renew and proliferate indefinitely in vitro. The two main types of PSCs, embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), share common features such as colony morphology, high expression of Oct4 and Nanog, and strong alkaline phosphatase activity. In recent years, increasing evidences suggest that telomere length represents another imp...

  4. Common stemness regulators of embryonic and cancer stem cells

    Institute of Scientific and Technical Information of China (English)

    Christiana; Hadjimichael; Konstantina; Chanoumidou; Natalia; Papadopoulou; Panagiota; Arampatzi; Joseph; Papamatheakis; Androniki; Kretsovali

    2015-01-01

    Pluripotency of embryonic stem cells(ESCs) and induced pluripotent stem cells is regulated by a well characterized gene transcription circuitry. The circuitry is assembled by ESC specific transcription factors, signal trans-ducing molecules and epigenetic regulators. Growing understanding of stem-like cells, albeit of more complex phenotypes, present in tumors(cancer stem cells), provides a common conceptual and research frame-work for basic and applied stem cell biology. In this review, we highlight current results on biomarkers, gene signatures, signaling pathways and epigenetic regulators that are common in embryonic and cancer stem cells. We discuss their role in determining the cell phenotype and finally, their potential use to design next generation biological and pharmaceutical approaches for regenerative medicine and cancer therapies.

  5. Laminin regulates PDGFRβ(+) cell stemness and muscle development.

    Science.gov (United States)

    Yao, Yao; Norris, Erin H; E Mason, Christopher; Strickland, Sidney

    2016-01-01

    Muscle-resident PDGFRβ(+) cells, which include pericytes and PW1(+) interstitial cells (PICs), play a dual role in muscular dystrophy. They can either undergo myogenesis to promote muscle regeneration or differentiate into adipocytes and other cells to compromise regeneration. How the differentiation and fate determination of PDGFRβ(+) cells are regulated, however, remains unclear. Here, by utilizing a conditional knockout mouse line, we report that PDGFRβ(+) cell-derived laminin inhibits their proliferation and adipogenesis, but is indispensable for their myogenesis. In addition, we show that laminin alone is able to partially reverse the muscle dystrophic phenotype in these mice at the molecular, structural and functional levels. Further RNAseq analysis reveals that laminin regulates PDGFRβ(+) cell differentiation/fate determination via gpihbp1. These data support a critical role of laminin in the regulation of PDGFRβ(+) cell stemness, identify an innovative target for future drug development and may provide an effective treatment for muscular dystrophy. PMID:27138650

  6. Autoimmunity: regulatory B cells--IL-35 and IL-21 regulate the regulators.

    Science.gov (United States)

    Tedder, Thomas F; Leonard, Warren J

    2014-08-01

    IL-21 regulates the activity and number of IL-10-producing regulatory B cells (B10 cells) that modulate immune responses and limit diverse autoimmune diseases. A new study demonstrates that IL-35 has a similar function. Identifying regulatory circuits that control B10-cell function in vivo might open the door to future treatments for autoimmune diseases.

  7. MicroRNAs as biomarkers for CNS cancer and other disorders.

    Science.gov (United States)

    De Smaele, Enrico; Ferretti, Elisabetta; Gulino, Alberto

    2010-06-18

    The use of miRNAs as biomarkers has gained growing interest in the last few years. Their role in regulating a great variety of targets and, as a consequence, multiple pathways, makes their use in diagnostics a powerful tool to be exploited for early detection of disease, risk assessment and prognosis and for the design of innovative therapeutic strategies. While still not fully validated, profiling of blood cells, exosomes or body fluid miRNAs would represent a tremendous and promising advance in non-invasive diagnostics of CNS disorders. A major challenge is represented by technological aspects of miRNA detection and discovery aiming to genome-wide high throughput, sensitive and accurate analysis. Although there is much to be learned in the field, this review will highlight the potential role of miRNA as a new class of biomarkers in several CNS disorders, including neurodegenerative diseases such as Alzheimer, Huntington and Parkinson diseases, schizophrenia and autism as well as different types of cancer (e.g. gliomas and medulloblastomas).

  8. The DOCK protein sponge binds to ELMO and functions in Drosophila embryonic CNS development.

    Directory of Open Access Journals (Sweden)

    Bridget Biersmith

    Full Text Available Cell morphogenesis, which requires rearrangement of the actin cytoskeleton, is essential to coordinate the development of tissues such as the musculature and nervous system during normal embryonic development. One class of signaling proteins that regulate actin cytoskeletal rearrangement is the evolutionarily conserved CDM (C. elegansCed-5, human DOCK180, DrosophilaMyoblast city, or Mbc family of proteins, which function as unconventional guanine nucleotide exchange factors for the small GTPase Rac. This CDM-Rac protein complex is sufficient for Rac activation, but is enhanced upon the association of CDM proteins with the ELMO/Ced-12 family of proteins. We identified and characterized the role of Drosophila Sponge (Spg, the vertebrate DOCK3/DOCK4 counterpart as an ELMO-interacting protein. Our analysis shows Spg mRNA and protein is expressed in the visceral musculature and developing nervous system, suggesting a role for Spg in later embryogenesis. As maternal null mutants of spg die early in development, we utilized genetic interaction analysis to uncover the role of Spg in central nervous system (CNS development. Consistent with its role in ELMO-dependent pathways, we found genetic interactions with spg and elmo mutants exhibited aberrant axonal defects. In addition, our data suggests Ncad may be responsible for recruiting Spg to the membrane, possibly in CNS development. Our findings not only characterize the role of a new DOCK family member, but help to further understand the role of signaling downstream of N-cadherin in neuronal development.

  9. Nanotechnology in the regulation of stem cell behavior

    Science.gov (United States)

    Wu, King-Chuen; Tseng, Ching-Li; Wu, Chi-Chang; Kao, Feng-Chen; Tu, Yuan-Kun; So, Edmund C.; Wang, Yang-Kao

    2013-10-01

    Stem cells are known for their potential to repair damaged tissues. The adhesion, growth and differentiation of stem cells are likely controlled by the surrounding microenvironment which contains both chemical and physical cues. Physical cues in the microenvironment, for example, nanotopography, were shown to play important roles in stem cell fate decisions. Thus, controlling stem cell behavior by nanoscale topography has become an important issue in stem cell biology. Nanotechnology has emerged as a new exciting field and research from this field has greatly advanced. Nanotechnology allows the manipulation of sophisticated surfaces/scaffolds which can mimic the cellular environment for regulating cellular behaviors. Thus, we summarize recent studies on nanotechnology with applications to stem cell biology, including the regulation of stem cell adhesion, growth, differentiation, tracking and imaging. Understanding the interactions of nanomaterials with stem cells may provide the knowledge to apply to cell-scaffold combinations in tissue engineering and regenerative medicine.

  10. Cell adhesion in regulation of asymmetric stem cell division

    OpenAIRE

    Yamashita, Yukiko M

    2010-01-01

    Adult stem cells inevitably communicate with their cellular neighbors within the tissues they sustain. Indeed, such communication, particularly with components of the stem cell niche, is essential for many aspects of stem cell behavior, including the maintenance of stem cell identity and asymmetric cell division. Cell adhesion mediates this communication by placing stem cells in close proximity to the signaling source and by providing a polarity cue that orients stem cells. Here, I review the...

  11. Knowledge-Based, Central Nervous System (CNS) Lead Selection and Lead Optimization for CNS Drug Discovery.

    Science.gov (United States)

    Ghose, Arup K; Herbertz, Torsten; Hudkins, Robert L; Dorsey, Bruce D; Mallamo, John P

    2012-01-18

    The central nervous system (CNS) is the major area that is affected by aging. Alzheimer's disease (AD), Parkinson's disease (PD), brain cancer, and stroke are the CNS diseases that will cost trillions of dollars for their treatment. Achievement of appropriate blood-brain barrier (BBB) penetration is often considered a significant hurdle in the CNS drug discovery process. On the other hand, BBB penetration may be a liability for many of the non-CNS drug targets, and a clear understanding of the physicochemical and structural differences between CNS and non-CNS drugs may assist both research areas. Because of the numerous and challenging issues in CNS drug discovery and the low success rates, pharmaceutical companies are beginning to deprioritize their drug discovery efforts in the CNS arena. Prompted by these challenges and to aid in the design of high-quality, efficacious CNS compounds, we analyzed the physicochemical property and the chemical structural profiles of 317 CNS and 626 non-CNS oral drugs. The conclusions derived provide an ideal property profile for lead selection and the property modification strategy during the lead optimization process. A list of substructural units that may be useful for CNS drug design was also provided here. A classification tree was also developed to differentiate between CNS drugs and non-CNS oral drugs. The combined analysis provided the following guidelines for designing high-quality CNS drugs: (i) topological molecular polar surface area of <76 Å(2) (25-60 Å(2)), (ii) at least one (one or two, including one aliphatic amine) nitrogen, (iii) fewer than seven (two to four) linear chains outside of rings, (iv) fewer than three (zero or one) polar hydrogen atoms, (v) volume of 740-970 Å(3), (vi) solvent accessible surface area of 460-580 Å(2), and (vii) positive QikProp parameter CNS. The ranges within parentheses may be used during lead optimization. One violation to this proposed profile may be acceptable. The

  12. Regulated expression of erythropoietin by two human hepatoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, M.A.; Glass, G.A.; Cunningham, J.M.; Bunn, H.F.

    1987-11-01

    The development of a cell culture system that produces erythropoietin (Epo) in a regulated manner has been the focus of much effort. The authors have screened multiple renal and hepatic cell lines for either constitutive or regulated expression of Epo. Only the human hepatoma cell lines, Hep3B and HepG2, made significant amounts of Epo as measured both by radioimmunoassay and in vitro bioassay (as much as 330 milliunits per 10/sup 6/ cells in 24 hr). The constitutive production of Epo increased dramatically as a function of cell density in both cell lines. At cell densities < 3.3 x 10/sup 5/ cells per cm/sup 2/, there was little constitutive release of Epo in the medium. With Hep3B cells grown at low cell densities, a mean 18-fold increase in Epo expression was seen in response to hypoxia and a 6-fold increase was observed in response to incubation in medium containing 50 ..mu..M cobalt(II) chloride. At similar low cell densities, Epo production in HepG2 cells could be enhanced an average of about 3-fold by stimulation with either hypoxia or cobalt(II) chloride. Upon such stimulation, both cell lines demonstrated markedly elevated levels of Epo mRNA. Hence, both Hep3B and HepG2 cell lines provide an excellent in vitro system in which to study the physiological regulation of Epo expression.

  13. Astroglial heterogeneity closely reflects the neuronal-defined anatomy of the adult murine CNS

    OpenAIRE

    EMSLEY, JASON G.; Macklis, Jeffrey D.

    2006-01-01

    Astroglia comprise an extremely morphologically diverse cell type that have crucial roles in neural development and function. Nonetheless, distinct regions of the CNS have traditionally been defined by the phenotypic characteristics and connectivity of neuros. In a complementary fashion, we present evidence that discrete regions of the adult CNS can be delineated based solely on the morphology, density and proliferation rates of astroglia. We used transgenic hGFAP-GFP mice in which robust exp...

  14. Epigenetic Regulation of Adaptive NK Cell Diversification.

    Science.gov (United States)

    Tesi, Bianca; Schlums, Heinrich; Cichocki, Frank; Bryceson, Yenan T

    2016-07-01

    Natural killer (NK) cells were previously considered to represent short-lived, innate lymphocytes. However, mouse models have revealed expansion and persistence of differentiated NK cell subsets in response to cytomegalovirus (CMV) infection, paralleling antigen-specific T cell differentiation. Congruently, analyses of humans have uncovered CMV-associated NK cell subsets characterized by epigenetic diversification processes that lead to altered target cell specificities and functional capacities. Here, focusing on responses to viruses, we review similarities and differences between mouse and human adaptive NK cells, identifying molecular analogies that may be key to transcriptional reprogramming and functional alterations. We discuss possible molecular mechanisms underlying epigenetic diversification and hypothesize that processes driving epigenetic diversification may represent a more widespread mechanism for fine-tuning and optimization of cellular immunity.

  15. Regulation of Germinal Center Reactions by B and T Cells

    Directory of Open Access Journals (Sweden)

    Yeonseok Chung

    2013-10-01

    Full Text Available Break of B cell tolerance to self-antigens results in the development of autoantibodies and, thus, leads to autoimmunity. How B cell tolerance is maintained during active germinal center (GC reactions is yet to be fully understood. Recent advances revealed several subsets of T cells and B cells that can positively or negatively regulate GC B cell responses in vivo. IL-21-producing CXCR5+ CD4+ T cells comprise a distinct lineage of helper T cells—termed follicular helper T cells (TFH—that can provide help for the development of GC reactions where somatic hypermutation and affinity maturation take place. Although the function of TFH cells is beneficial in generating high affinity antibodies against infectious agents, aberrant activation of TFH cell or B cell to self-antigens results in autoimmunity. At least three subsets of immune cells have been proposed as regulatory cells that can limit such antibody-mediated autoimmunity, including follicular regulatory T cells (TFR, Qa-1 restricted CD8+ regulatory T cells (CD8+TREG, and regulatory B cells (BREG. In this review, we will discuss our current understanding of GC B cell regulation with specific emphasis on the newly identified immune cell subsets involved in this process.

  16. TLR3 deficiency renders astrocytes permissive to herpes simplex virus infection and facilitates establishment of CNS infection in mice

    DEFF Research Database (Denmark)

    Reinert, Line; Harder, Louis Andreas; Holm, Christian;

    2012-01-01

    , it is not known what cell type mediates the role of TLR3 in the immunological control of HSV, and it is not known whether TLR3 sensing occurs prior to or after CNS entry. Here, we show that in mice TLR3 provides early control of HSV-2 infection immediately after entry into the CNS by mediating type I IFN...

  17. YAP regulates S-phase entry in endothelial cells.

    Directory of Open Access Journals (Sweden)

    Zhewei Shen

    Full Text Available The Hippo pathway regulates cell proliferation and apoptosis through the Yes-associated protein (YAP transcriptional activator. YAP has a well-described role in promoting cell proliferation and survival, but the precise mechanisms and transcriptional targets that underlie these properties are still unclear and likely context-dependent. We found, using siRNA-mediated knockdown, that YAP is required for proliferation in endothelial cells but not HeLa cells. Specifically, YAP is required for S-phase entry and its absence causes cells to accumulate in G1. Microarray analysis suggests that YAP mediates this effect by regulating the transcription of genes involved in the assembly and/or firing of replication origins and homologous recombination of DNA. These findings thus provide insight into the molecular mechanisms by which YAP regulates cell cycle progression.

  18. Nanotechnology in the regulation of stem cell behavior

    International Nuclear Information System (INIS)

    Stem cells are known for their potential to repair damaged tissues. The adhesion, growth and differentiation of stem cells are likely controlled by the surrounding microenvironment which contains both chemical and physical cues. Physical cues in the microenvironment, for example, nanotopography, were shown to play important roles in stem cell fate decisions. Thus, controlling stem cell behavior by nanoscale topography has become an important issue in stem cell biology. Nanotechnology has emerged as a new exciting field and research from this field has greatly advanced. Nanotechnology allows the manipulation of sophisticated surfaces/scaffolds which can mimic the cellular environment for regulating cellular behaviors. Thus, we summarize recent studies on nanotechnology with applications to stem cell biology, including the regulation of stem cell adhesion, growth, differentiation, tracking and imaging. Understanding the interactions of nanomaterials with stem cells may provide the knowledge to apply to cell–scaffold combinations in tissue engineering and regenerative medicine. (review)

  19. Nanotechnology in the regulation of stem cell behavior

    Directory of Open Access Journals (Sweden)

    King-Chuen Wu, Ching-Li Tseng, Chi-Chang Wu, Feng-Chen Kao, Yuan-Kun Tu, Edmund C So and Yang-Kao Wang

    2013-01-01

    Full Text Available Stem cells are known for their potential to repair damaged tissues. The adhesion, growth and differentiation of stem cells are likely controlled by the surrounding microenvironment which contains both chemical and physical cues. Physical cues in the microenvironment, for example, nanotopography, were shown to play important roles in stem cell fate decisions. Thus, controlling stem cell behavior by nanoscale topography has become an important issue in stem cell biology. Nanotechnology has emerged as a new exciting field and research from this field has greatly advanced. Nanotechnology allows the manipulation of sophisticated surfaces/scaffolds which can mimic the cellular environment for regulating cellular behaviors. Thus, we summarize recent studies on nanotechnology with applications to stem cell biology, including the regulation of stem cell adhesion, growth, differentiation, tracking and imaging. Understanding the interactions of nanomaterials with stem cells may provide the knowledge to apply to cell–scaffold combinations in tissue engineering and regenerative medicine.

  20. Growth regulation of cultured human nevus cells.

    Science.gov (United States)

    Mancianti, M L; Györfi, T; Shih, I M; Valyi-Nagy, I; Levengood, G; Menssen, H D; Halpern, A C; Elder, D E; Herlyn, M

    1993-03-01

    Cells isolated from congenital melanocytic nevi and cultured in vitro have growth characteristics that resemble their premalignant stage in situ. A serum-free, chemically defined medium has been developed that allows continuous growth of established nevus cultures for up to several months. Like primary melanoma cells, nevus cells in high-calcium-containing W489 medium require insulin for growth. In contrast to melanoma cells, nevus cells in serum-free medium require the presence of alpha-melanocyte-stimulating hormone, which enhanced intracellular levels of cyclic adenosine monophosphate. In contrast to the requirements of normal human melanocytes from newborn foreskin, congenital nevus cells grow with less dependency on basic fibroblast growth factor (bFGF). Nevus cultures contain bFGF-like activity, and they express bFGF mRNA. Nevic cells of compound nevi also express bFGF mRNA in situ but only in the junctional areas. These results indicate that bFGF plays an important growth regulatory role for nevus cells in vitro and in vivo. PMID:8440904

  1. Histone Demethylase LSD1 Regulates Neural Stem Cell Proliferation▿

    OpenAIRE

    Sun, Guoqiang; Alzayady, Kamil; Stewart, Richard; Ye, Peng; Yang, Su; Li, Wendong; Shi, Yanhong

    2010-01-01

    Lysine-specific demethylase 1 (LSD1) functions as a transcriptional coregulator by modulating histone methylation. Its role in neural stem cells has not been studied. We show here for the first time that LSD1 serves as a key regulator of neural stem cell proliferation. Inhibition of LSD1 activity or knockdown of LSD1 expression led to dramatically reduced neural stem cell proliferation. LSD1 is recruited by nuclear receptor TLX, an essential neural stem cell regulator, to the promoters of TLX...

  2. Nkx2.2:Cre knock-in mouse line: a novel tool for pancreas- and CNS-specific gene deletion.

    Science.gov (United States)

    Balderes, Dina A; Magnuson, Mark A; Sussel, Lori

    2013-12-01

    Nkx2.2 is a homeodomain-containing transcriptional regulator necessary for the appropriate differentiation of ventral neuronal populations in the spinal cord and hindbrain, and endocrine cell populations in the pancreas and intestine. In each tissue, Nkx2.2 inactivation leads to reciprocal cell fate alterations. To confirm the cell fate changes are due to respecification of Nkx2.2-expressing progenitors and to provide a novel tool for lineage tracing in the pancreas and CNS, we generated an Nkx2.2:Cre mouse line by knocking in a Cre-EGFP cassette into the Nkx2.2 genomic locus and inactivating endogenous Nkx2.2. The R26R-CAG-LSL-tdTomato reporter was used to monitor the specificity and efficiency of Nkx2.2:Cre activity; the tomato reporter faithfully recapitulated endogenous Nkx2.2 expression and could be detected as early as embryonic day (e) 9.25 in the developing CNS and was initiated shortly thereafter at e9.5 in the pancreas. Lineage analyses in the CNS confirmed the cell populations thought to be derived from Nkx2.2-expressing progenitor domains. Furthermore, lineage studies verified Nkx2.2 expression in the earliest pancreatic progenitors that give rise to all cell types of the pancreas; however they also revealed more robust Cre activity in the dorsal versus ventral pancreas. Thus, the Nkx2.2:Cre line provides a novel tool for gene manipulations in the CNS and pancreas.

  3. Cell fate regulation in early mammalian development

    Science.gov (United States)

    Oron, Efrat; Ivanova, Natalia

    2012-08-01

    Preimplantation development in mammals encompasses a period from fertilization to implantation and results in formation of a blastocyst composed of three distinct cell lineages: epiblast, trophectoderm and primitive endoderm. The epiblast gives rise to the organism, while the trophectoderm and the primitive endoderm contribute to extraembryonic tissues that support embryo development after implantation. In many vertebrates, such as frog or fish, maternally supplied lineage determinants are partitioned within the egg. Cell cleavage that follows fertilization results in polarization of these factors between the individual blastomeres, which become restricted in their developmental fate. In contrast, the mouse oocyte and zygote lack clear polarity and, until the eight-cell stage, individual blastomeres retain the potential to form all lineages. How are cell lineages specified in the absence of a maternally supplied blueprint? This is a fundamental question in the field of developmental biology. The answer to this question lies in understanding the cell-cell interactions and gene networks involved in embryonic development prior to implantation and using this knowledge to create testable models of the developmental processes that govern cell fates. We provide an overview of classic and contemporary models of early lineage development in the mouse and discuss the emerging body of work that highlights similarities and differences between blastocyst development in the mouse and other mammalian species.

  4. Alectinib induced CNS radiation necrosis in an ALK+NSCLC patient with a remote (7 years) history of brain radiation.

    Science.gov (United States)

    Ou, Sai-Hong Ignatius; Weitz, Michael; Jalas, John R; Kelly, Daniel F; Wong, Vanessa; Azada, Michele C; Quines, Oliver; Klempner, Samuel J

    2016-06-01

    Alectinib is a second generation ALK inhibitor that has significant clinical activity in central nervous system (CNS) metastases in anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC). Pseudoprogression (PsP) due to radiation necrosis during alecitnib treatment of central nervous system (CNS) metastases from ALK-rearranged NSCLC as been reported. Hence, distinguishing radiation-related PsP from alectinib-induced radiographic changes is important to avoid erroneous early trial discontinuation and abandonment of an effective treatment. However, it remains difficult to assess casuality of radiation necrosis is related to recent direct radiation or induced by alectinib treatment or both. It is also unknown how long from previous radiation can alectinib still induce radiation necrosis. Here we reported a crizotinib-refractory ALK-positive NSCLC patient who develop radiation necrosis in one of his metastatic CNS lesions after approximately 12 months of alectinib treatment who otherwise had on-going CNS response on alectinib. His most recent radiation to his CNS metastases was 7 years prior to the start of alectinib. This case illustrates that in the setting of pror CNS radiation, given the significant clinical activity of alectinib in CNS metastases in ALK-positive NSCLC patients the risk of CNS radiation necrosis remains long after previous radiation to the CNS metastases has been completed and can occur after durable response of treatment. PMID:27133743

  5. Regulation of pulmonary inflammation by mesenchymal cells

    NARCIS (Netherlands)

    Alkhouri, Hatem; Poppinga, Wilfred Jelco; Tania, Navessa Padma; Ammit, Alaina; Schuliga, Michael

    2014-01-01

    Pulmonary inflammation and tissue remodelling are common elements of chronic respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and pulmonary hypertension (PH). In disease, pulmonary mesenchymal cells not only contribute to tissue

  6. Normal adult ramified microglia separated from other central nervous system macrophages by flow cytometric sorting: Phenotypic differences defined and direct ex vivo antigen presentation to myelin basic protein-reactive CD4{sup +} T cells compared

    Energy Technology Data Exchange (ETDEWEB)

    Ford, A.L.; Goodsall, A.L.; Sedgwick, J.D. [Centenary Institute of Cancer Medicine and Cell Biology, Sydney (Australia)] [and others

    1995-05-01

    Ramified microglia in the adult central nervous system (CNS) are the principal glial element up-regulating MHC class I and II expression in response to inflammatory events or neuronal damage. A proportion of these cells also express MHC class II constitutively in the normal CNS. The role of microglia as APCs for CD4{sup +} cells extravasating into the CNS remains undefined. In this study, using irradiation bone marrow chimeras in CD45-congenic rats, the phenotype CD45{sup low}CD11b/c{sup +} is shown to identify microglial cells specifically within the CNS. Highly purified populations of microglia and nonmicroglial but CNS-associated macrophages (CD45{sup high}CD11b/c{sup +}) have been obtained directly from the adult CNS, by using flow cytometric sorting. Morphologically, freshly isolated microglia vs other CNS macrophages are quite distinct. Of the two populations recovered from the normal CNS, it is the minority CD45{sup high}CD11 b/c{sup +} transitional macrophage population, and not microglia, that is the effective APC for experimental autoimmune encephalomyelitis-inducing CD4{sup +} myelin basic protein (MBP)-reactive T cells. CD45{sup high}CD11b/c{sup +} CNS macrophages also stimulate MBP-reactive T cells without addition of MBP to culture suggesting presentation of endogenous Ag. This is the first study in which microglia vs other CNS macrophages have been analyzed for APC ability directly from the CNS, with substantial cross-contamination between the two populations eliminated. The heterogeneity of these populations in terms of APC function is clearly demonstrated. Evidence is still lacking that adult CNS microglia have the capacity to interact with and stimulate CD4{sup +} T cells to proliferate or secrete IL-2. 60 refs., 6 figs., 1 tab.

  7. Convulsant bicuculline modifies CNS muscarinic receptor affinity

    Directory of Open Access Journals (Sweden)

    Rodríguez de Lores Arnaiz Georgina

    2006-04-01

    Full Text Available Abstract Background Previous work from this laboratory has shown that the administration of the convulsant drug 3-mercaptopropionic acid (MP, a GAD inhibitor, modifies not only GABA synthesis but also binding of the antagonist [3H]-quinuclidinyl benzilate ([3H]-QNB to central muscarinic receptors, an effect due to an increase in affinity without modifications in binding site number. The cholinergic system has been implicated in several experimental epilepsy models and the ability of acetylcholine to regulate neuronal excitability in the neocortex is well known. To study the potential relationship between GABAergic and cholinergic systems with seizure activity, we analyzed the muscarinic receptor after inducing seizure by bicuculline (BIC, known to antagonize the GABA-A postsynaptic receptor subtype. Results We analyzed binding of muscarinic antagonist [3H]-QNB to rat CNS membranes after i.p. administration of BIC at subconvulsant (1.0 mg/kg and convulsant (7.5 mg/kg doses. Subconvulsant BIC dose failed to develop seizures but produced binding alteration in the cerebellum and hippocampus with roughly 40% increase and 10% decrease, respectively. After convulsant BIC dose, which invariably led to generalized tonic-clonic seizures, binding increased 36% and 15% to cerebellar and striatal membranes respectively, but decreased 12% to hippocampal membranes. Kd value was accordingly modified: with the subconvulsant dose it decreased 27% in cerebellum whereas it increased 61% in hippocampus; with the convulsant dose, Kd value decreased 33% in cerebellum but increased 85% in hippocampus. No change in receptor number site was found, and Hill number was invariably close to unity. Conclusion Results indicate dissimilar central nervous system area susceptibility of muscarinic receptor to BIC. Ligand binding was modified not only by a convulsant BIC dose but also by a subconvulsant dose, indicating that changes are not attributable to the seizure process

  8. c-Myc regulates cell proliferation during lens development.

    Directory of Open Access Journals (Sweden)

    Gabriel R Cavalheiro

    Full Text Available Myc protooncogenes play important roles in the regulation of cell proliferation, growth, differentiation and survival during development. In various developing organs, c-myc has been shown to control the expression of cell cycle regulators and its misregulated expression is detected in many human tumors. Here, we show that c-myc gene (Myc is highly expressed in developing mouse lens. Targeted deletion of c-myc gene from head surface ectoderm dramatically impaired ocular organogenesis, resulting in severe microphtalmia, defective anterior segment development, formation of a lens stalk and/or aphakia. In particular, lenses lacking c-myc presented thinner epithelial cell layer and growth impairment that was detectable soon after its inactivation. Defective development of c-myc-null lens was not caused by increased cell death of lens progenitor cells. Instead, c-myc loss reduced cell proliferation, what was associated with an ectopic expression of Prox1 and p27(Kip1 proteins within epithelial cells. Interestingly, a sharp decrease in the expression of the forkhead box transcription factor Foxe3 was also observed following c-myc inactivation. These data represent the first description of the physiological roles played by a Myc family member in mouse lens development. Our findings support the conclusion that c-myc regulates the proliferation of lens epithelial cells in vivo and may, directly or indirectly, modulate the expression of classical cell cycle regulators in developing mouse lens.

  9. FXR: a metabolic regulator and cell protector

    Institute of Scientific and Technical Information of China (English)

    Yan-Dong Wang; Wei-Dong Chen; David D Moore; Wendong Huang

    2008-01-01

    Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily of ligand-activated transcription fac-tors. As a metabolic regulator, FXR plays key roles in bile acid, cholesterol, lipid, and glucose metabolism. Therefore, FXR is a potential drug target for a number of metabolic disorders, especially those related to the metabolic syn-drome. More recently, our group and others have extended the functions of FXR to more than metabolic regulation, which include anti-bacterial growth in intestine, liver regeneration, and hepatocarcinogenesis. These new findings suggest that FXR has much broader roles than previously thought, and also higl light FXR as a drug target for mul-tiple diseases. This review summarizes the basic information of FXR but focuses on its new functions.

  10. Epigenetic regulator Lid maintains germline stem cells through regulating JAK-STAT signaling pathway activity

    Directory of Open Access Journals (Sweden)

    Lama Tarayrah

    2015-11-01

    Full Text Available Signaling pathways and epigenetic mechanisms have both been shown to play essential roles in regulating stem cell activity. While the role of either mechanism in this regulation is well established in multiple stem cell lineages, how the two mechanisms interact to regulate stem cell activity is not as well understood. Here we report that in the Drosophila testis, an H3K4me3-specific histone demethylase encoded by little imaginal discs (lid maintains germline stem cell (GSC mitotic index and prevents GSC premature differentiation. Lid is required in germ cells for proper expression of the Stat92E transcription factor, the downstream effector of the Janus kinase signal transducer and activator of transcription (JAK-STAT signaling pathway. Our findings support a germ cell autonomous role for the JAK-STAT pathway in maintaining GSCs and place Lid as an upstream regulator of this pathway. Our study provides new insights into the biological functions of a histone demethylase in vivo and sheds light on the interaction between epigenetic mechanisms and signaling pathways in regulating stem cell activities.

  11. Regulated genes in mesenchymal stem cells and gastriccancer

    Institute of Scientific and Technical Information of China (English)

    Shihori Tanabe; Kazuhiko Aoyagi; Hiroshi Yokozaki; Hiroki Sasaki

    2015-01-01

    AIM To investigate the genes regulated in mesenchymalstem cells (MSCs) and diffuse-type gastric cancer (GC),gene expression was analyzed.METHODS: Gene expression of MSCs and diffuse-typeGC cells were analyzed by microarray. Genes relatedto stem cells, cancer and the epithelial-mesenchymaltransition (EMT) were extracted from human genelists using Gene Ontology and reference information.Gene panels were generated, and messenger RNAgene expression in MSCs and diffuse-type GC cells wasanalyzed. Cluster analysis was performed using the NCSSsoftware.RESULTS: The gene expression of regulator of G-proteinsignaling 1 (RGS1) was up-regulated in diffuse-type GCcells compared with MSCs. A panel of stem-cell relatedgenes and genes involved in cancer or the EMT wereexamined. Stem-cell related genes, such as growtharrest-specific 6, musashi RNA-binding protein 2 andhairy and enhancer of split 1 (Drosophila), NOTCHfamily genes and Notch ligands, such as delta-like 1(Drosophila) and Jagged 2, were regulated.CONCLUSION: Expression of RGS1 is up-regulated,and genes related to stem cells and NOTCH signalingare altered in diffuse-type GC compared with MSCs.

  12. Regulation of Hematopoietic Stem Cells by Bone Marrow Stromal Cells

    OpenAIRE

    Anthony, Bryan; Link, Daniel C.

    2013-01-01

    Hematopoietic stem cells (HSCs) reside in specialized microenvironments (niches) in the bone marrow. The stem cell niche is thought to provide signals that support key HSC properties, including self-renewal capacity and long-term multilineage repopulation ability. The stromal cells that comprise the stem cell niche and the signals that they generate that support HSC function are the subjects of intense investigation. Here we review the complex and diverse stromal cell populations that reside ...

  13. miR-148 regulates Mitf in melanoma cells.

    Directory of Open Access Journals (Sweden)

    Benedikta S Haflidadóttir

    Full Text Available The Microphthalmia associated transcription factor (Mitf is an important regulator in melanocyte development and has been shown to be involved in melanoma progression. The current model for the role of Mitf in melanoma assumes that the total activity of the protein is tightly regulated in order to secure cell proliferation. Previous research has shown that regulation of Mitf is complex and involves regulation of expression, splicing, protein stability and post-translational modifications. Here we show that microRNAs (miRNAs are also involved in regulating Mitf in melanoma cells. Sequence analysis revealed conserved binding sites for several miRNAs in the Mitf 3'UTR sequence. Furthermore, miR-148 was shown to affect Mitf mRNA expression in melanoma cells through a conserved binding site in the 3'UTR sequence of mouse and human Mitf. In addition we confirm the previously reported effects of miR-137 on Mitf. Other miRNAs, miR-27a, miR-32 and miR-124 which all have conserved binding sites in the Mitf 3'UTR sequence did not have effects on Mitf. Our data show that miR-148 and miR-137 present an additional level of regulating Mitf expression in melanocytes and melanoma cells. Loss of this regulation, either by mutations or by shortening of the 3'UTR sequence, is therefore a likely factor in melanoma formation and/or progression.

  14. MAPK signal pathways in the regulation of cell proliferation in mammalian cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    MAPK families play an important role in complex cellular programs like proliferation, differentiation,development, transformation, and apoptosis. At least three MAPK families have been characterized: extracellular signal-regulated kinase (ERK), Jun kinase (JNK/SAPK) and p38 MAPK. The above effects are fulfilled by regulation of cell cycle engine and other cell proliferation related proteins. In this paper we discussed their functions and cooperation with other signal pathways in regulation of cell proliferation.

  15. Evolution of cell cycle control: same molecular machines, different regulation

    DEFF Research Database (Denmark)

    de Lichtenberg, Ulrik; Jensen, Thomas Skøt; Brunak, Søren;

    2007-01-01

    Decades of research has together with the availability of whole genomes made it clear that many of the core components involved in the cell cycle are conserved across eukaryotes, both functionally and structurally. These proteins are organized in complexes and modules that are activated or...... layers of regulation together control the activity of cell cycle complexes and how this regulation has evolved. The results show surprisingly poor conservation of both the transcriptional and the post-translation regulation of individual genes and proteins; however, the changes in one layer of regulation...... are often mirrored by changes in other layers, implying that independent layers of control coevolve. By taking a bird's eye view of the cell cycle, we demonstrate how the modular organization of cellular systems possesses a built-in flexibility, which allows evolution to find many different solutions...

  16. Cell cycle regulation of human WEE1.

    OpenAIRE

    McGowan, C H; Russell, P.

    1995-01-01

    WEE1 kinase negatively regulates entry into mitosis by catalyzing the inhibitory tyrosine phosphorylation of CDC2/cyclin B kinase. We report here an investigation of human WEE1. Endogenous WEE1 migrates as an approximately 94 kDa protein in SDS-PAGE, substantially larger than the 49 kDa protein encoded by the original human WEE1 cDNA clone that was truncated at the 5'-end. Antibody depletion experiments demonstrate that WEE1 accounts for most of the activity that phosphorylates CDC2 on Tyr15 ...

  17. An invertebrate model for CNS drug discovery

    DEFF Research Database (Denmark)

    Al-Qadi, Sonia; Schiøtt, Morten; Hansen, Steen Honoré;

    2015-01-01

    BACKGROUND: ABC efflux transporters at the blood brain barrier (BBB), namely the P-glycoprotein (P-gp), restrain the development of central nervous system (CNS) drugs. Consequently, early screening of CNS drug candidates is pivotal to identify those affected by efflux activity. Therefore, simple...... barriers. CONCLUSION: Findings suggest a conserved mechanism of brain efflux activity between insects and vertebrates, confirming that this model holds promise for inexpensive and high-throughput screening relative to in vivo models, for CNS drug discovery......., high-throughput and predictive screening models are required. The grasshopper (locust) has been developed as an invertebrate in situ model for BBB permeability assessment, as it has shown similarities to vertebrate models. METHODS: Transcriptome profiling of ABC efflux transporters in the locust brain...

  18. Tetracycline-Regulated Suppression of Amber Codons in Mammalian Cells

    OpenAIRE

    Park, Ho-Jin; RajBhandary, Uttam L.

    1998-01-01

    As an approach to inducible suppression of nonsense mutations in mammalian cells, we described recently an amber suppression system in mammalian cells dependent on coexpression of Escherichia coli glutaminyl-tRNA synthetase (GlnRS) along with the E. coli glutamine-inserting amber suppressor tRNA. Here, we report on tetracycline-regulated expression of the E. coli GlnRS gene and, thereby, tetracycline-regulated suppression of amber codons in mammalian HeLa and COS-1 cells. The E. coli GlnRS co...

  19. How stem cells speak with host immune cells in inflammatory brain diseases.

    Science.gov (United States)

    Pluchino, Stefano; Cossetti, Chiara

    2013-09-01

    Advances in stem cell biology have raised great expectations that diseases and injuries of the central nervous system (CNS) may be ameliorated by the development of non-hematopoietic stem cell medicines. Yet, the application of adult stem cells as CNS therapeutics is challenging and the interpretation of some of the outcomes ambiguous. In fact, the initial idea that stem cell transplants work only via structural cell replacement has been challenged by the observation of consistent cellular signaling between the graft and the host. Cellular signaling is the foundation of coordinated actions and flexible responses, and arises via networks of exchanging and interacting molecules that transmit patterns of information between cells. Sustained stem cell graft-to-host communication leads to remarkable trophic effects on endogenous brain cells and beneficial modulatory actions on innate and adaptive immune responses in vivo, ultimately promoting the healing of the injured CNS. Among a number of adult stem cell types, mesenchymal stem cells (MSCs) and neural stem/precursor cells (NPCs) are being extensively investigated for their ability to signal to the immune system upon transplantation in experimental CNS diseases. Here, we focus on the main cellular signaling pathways that grafted MSCs and NPCs use to establish a therapeutically relevant cross talk with host immune cells, while examining the role of inflammation in regulating some of the bidirectionality of these communications. We propose that the identification of the players involved in stem cell signaling might contribute to the development of innovative, high clinical impact therapeutics for inflammatory CNS diseases.

  20. Mechanism of T cell regulation by microRNAs

    International Nuclear Information System (INIS)

    MicroRNAs (miRNAs) are small, non-coding single-stranded RNAs that can modulate target gene expression at post-transcriptional level and participate in cell proliferation, differentiation, and apoptosis. T cells have important functions in acquired immune response; miRNAs regulate this immune response by targeting the mRNAs of genes involved in T cell development, proliferation, differentiation, and function. For instance, miR-181 family members function in progression by targeting Bcl2 and CD69, among others. MiR-17 to miR-92 clusters function by binding to CREB1, PTEN, and Bim. Considering that the suppression of T cell-mediated immune responses against tumor cells is involved in cancer progression, we should investigate the mechanism by which miRNA regulates T cells to develop new approaches for cancer treatment

  1. Metabolic regulation of regulatory T cell development and function

    Directory of Open Access Journals (Sweden)

    David John Coe

    2014-11-01

    Full Text Available It is now well established that the effector T cell (Teff response is regulated by a series of metabolic switches. Quiescent T cells predominantly require ATP-generating processes, whereas proliferating Teff require high metabolic flux through growth-promoting pathways, such as glycolysis. Pathways that control metabolism and immune cell function are intimately linked, and changes in cell metabolism at both the cell and system levels have been shown to enhance or suppress specific T cell effector functions. Furthermore, functionally distinct T cell subsets have been shown to require distinct energetic and biosynthetic pathways to support their specific functional needs. In particular, naturally occurring regulatory T cells (Treg are characterized by a unique metabolic signature distinct to that of conventional Teff cells. We here briefly review the signaling pathways that control Treg metabolism and how this metabolic phenotype integrates their differentiation and function. Ultimately, these metabolic features may provide new opportunities for the therapeutic modulation of unwanted immune responses.

  2. TGF-β Signaling Regulates Pancreatic β-Cell Proliferation through Control of Cell Cycle Regulator p27 Expression

    International Nuclear Information System (INIS)

    Proliferation of pancreatic β-cells is an important mechanism underlying β-cell mass adaptation to metabolic demands. Increasing β-cell mass by regeneration may ameliorate or correct both type 1 and type 2 diabetes, which both result from inadequate production of insulin by β-cells of the pancreatic islet. Transforming growth factor β (TGF-β) signaling is essential for fetal development and growth of pancreatic islets. In this study, we exposed HIT-T15, a clonal pancreatic β-cell line, to TGF-β signaling. We found that inhibition of TGF-β signaling promotes proliferation of the cells significantly, while TGF-β signaling stimulation inhibits proliferation of the cells remarkably. We confirmed that this proliferative regulation by TGF-β signaling is due to the changed expression of the cell cycle regulator p27. Furthermore, we demonstrated that there is no observed effect on transcriptional activity of p27 by TGF-β signaling. Our data show that TGF-β signaling mediates the cell-cycle progression of pancreatic β-cells by regulating the nuclear localization of CDK inhibitor, p27. Inhibition of TGF-β signaling reduces the nuclear accumulation of p27, and as a result this inhibition promotes proliferation of β-cells

  3. Neural progenitor cells regulate microglia functions and activity.

    Science.gov (United States)

    Mosher, Kira I; Andres, Robert H; Fukuhara, Takeshi; Bieri, Gregor; Hasegawa-Moriyama, Maiko; He, Yingbo; Guzman, Raphael; Wyss-Coray, Tony

    2012-11-01

    We found mouse neural progenitor cells (NPCs) to have a secretory protein profile distinct from other brain cells and to modulate microglial activation, proliferation and phagocytosis. NPC-derived vascular endothelial growth factor was necessary and sufficient to exert at least some of these effects in mice. Thus, neural precursor cells may not only be shaped by microglia, but also regulate microglia functions and activity.

  4. Plant guard cell anion channel SLAC1 regulates stomatal closure

    OpenAIRE

    Vahisalu, Triin

    2010-01-01

    Plants are rooted to their growth place; therefore it is important that they react adequately to changes in environmental conditions. Stomatal pores, which are formed of a pair of guard cells in leaf epidermis, regulate plant gas-exchange. Importantly, guard cells protect the plant from desiccation in drought conditions by reducing the aperture of the stomatal pore. They serve also as the first barrier against the major air pollutant ozone, but the behaviour of guard cells during ozone expo...

  5. Insulin and glucagon regulate pancreatic α-cell proliferation.

    Directory of Open Access Journals (Sweden)

    Zhuo Liu

    Full Text Available Type 2 diabetes mellitus (T2DM results from insulin resistance and β-cell dysfunction, in the setting of hyperglucagonemia. Glucagon is a 29 amino acid peptide hormone, which is secreted from pancreatic α cells: excessively high circulating levels of glucagon lead to excessive hepatic glucose output. We investigated if α-cell numbers increase in T2DM and what factor (s regulate α-cell turnover. Lepr(db/Lepr(db (db/db mice were used as a T2DM model and αTC1 cells were used to study potential α-cell trophic factors. Here, we demonstrate that in db/db mice α-cell number and plasma glucagon levels increased as diabetes progressed. Insulin treatment (EC50 = 2 nM of α cells significantly increased α-cell proliferation in a concentration-dependent manner compared to non-insulin-treated α cells. Insulin up-regulated α-cell proliferation through the IR/IRS2/AKT/mTOR signaling pathway, and increased insulin-mediated proliferation was prevented by pretreatment with rapamycin, a specific mTOR inhibitor. GcgR antagonism resulted in reduced rates of cell proliferation in αTC1 cells. In addition, blockade of GcgRs in db/db mice improved glucose homeostasis, lessened α-cell proliferation, and increased intra-islet insulin content in β cells in db/db mice. These studies illustrate that pancreatic α-cell proliferation increases as diabetes develops, resulting in elevated plasma glucagon levels, and both insulin and glucagon are trophic factors to α-cells. Our current findings suggest that new therapeutic strategies for the treatment of T2DM may include targeting α cells and glucagon.

  6. Upregulation of Phagocytic Clearance of Apoptotic Cells by Autoimmune Regulator

    Institute of Scientific and Technical Information of China (English)

    石亮; 胡丽华; 李一荣

    2010-01-01

    To investigate the effect of autoimmune regulator(AIRE) on phagocytic clearance of apoptotic cells,a recombinant expression vector containing full-length human AIRE cDNA was transfected into 16HBE cells.After incubation with transfected 16HBE cells,engulfment of apoptotic HL-60 cells induced by camptothecin was detected by myeloperoxidase(MPO) staining.The change in the expression of Rac 1 in transfected 16HBE cells was determined by RT-PCR and Western blotting.The results showed that the phagocytosis perce...

  7. Regulation of cell cycle by the anaphase spindle midzone

    Directory of Open Access Journals (Sweden)

    Sluder Greenfield

    2004-12-01

    Full Text Available Abstract Background A number of proteins accumulate in the spindle midzone and midbody of dividing animal cells. Besides proteins essential for cytokinesis, there are also components essential for interphase functions, suggesting that the spindle midzone and/or midbody may play a role in regulating the following cell cycle. Results We microsurgically severed NRK epithelial cells during anaphase or telophase, such that the spindle midzone/midbody was associated with only one of the daughter cells. Time-lapse recording of cells severed during early anaphase indicated that the cell with midzone underwent cytokinesis-like cortical contractions and progressed normally through the interphase, whereas the cell without midzone showed no cortical contraction and an arrest or substantial delay in the progression of interphase. Similar microsurgery during telophase showed a normal progression of interphase for both daughter cells with or without the midbody. Microsurgery of anaphase cells treated with cytochalasin D or nocodazole indicated that interphase progression was independent of cortical ingression but dependent on microtubules. Conclusions We conclude that the mitotic spindle is involved in not only the separation of chromosomes but also the regulation of cell cycle. The process may involve activation of components in the spindle midzone that are required for the cell cycle, and/or degradation of components that are required for cytokinesis but may interfere with the cell cycle.

  8. Regulation of embryonic cell adhesion by the prion protein.

    Directory of Open Access Journals (Sweden)

    Edward Málaga-Trillo

    2009-03-01

    Full Text Available Prion proteins (PrPs are key players in fatal neurodegenerative disorders, yet their physiological functions remain unclear, as PrP knockout mice develop rather normally. We report a strong PrP loss-of-function phenotype in zebrafish embryos, characterized by the loss of embryonic cell adhesion and arrested gastrulation. Zebrafish and mouse PrP mRNAs can partially rescue this knockdown phenotype, indicating conserved PrP functions. Using zebrafish, mouse, and Drosophila cells, we show that PrP: (1 mediates Ca(+2-independent homophilic cell adhesion and signaling; and (2 modulates Ca(+2-dependent cell adhesion by regulating the delivery of E-cadherin to the plasma membrane. In vivo time-lapse analyses reveal that the arrested gastrulation in PrP knockdown embryos is due to deficient morphogenetic cell movements, which rely on E-cadherin-based adhesion. Cell-transplantation experiments indicate that the regulation of embryonic cell adhesion by PrP is cell-autonomous. Moreover, we find that the local accumulation of PrP at cell contact sites is concomitant with the activation of Src-related kinases, the recruitment of reggie/flotillin microdomains, and the reorganization of the actin cytoskeleton, consistent with a role of PrP in the modulation of cell adhesion via signaling. Altogether, our data uncover evolutionarily conserved roles of PrP in cell communication, which ultimately impinge on the stability of adherens cell junctions during embryonic development.

  9. Cell volume regulation in goldfish intestinal mucosa.

    Science.gov (United States)

    Groot, J A

    1981-11-01

    1. Ion and water content of goldfish intestinal mucosa, stripped free from muscular layers were measured under various incubation conditions. 2. Ouabain induces an increase in cation content that is electrically compensated for by chloride. The increase in solute content is accompanied by an increase in water content. 3. When extracellular chloride is partially replaced by sulphate, ouabain does induce cell shrinkage. 4. Anoxia induces a rapid increase in cell volume that is restored by oxygenation of the incubation solution. Ouabain prevents the restoration of volume. 5. It is concluded that the classical ouabain-sensitive Na/K pump participates in the maintenance of cellular volume. We suggest that the constancy in volume after ouabain poisoning as is reported for many tissues might be due to a low chloride conductance of its membranes. 6. Anisotonic media (range: 0.6-1.2 isotonicity), made by variation on mannitol concentration, induce changes in cell water content that deviates from the simplified van't Hoff equation by about 10%. No change in water content after the initial increase was found. 7. We conclude that goldfish enterocytes do not possess a mechanism for rapid volume readjustment. PMID:7322833

  10. Regulated cell-to-cell variation in a cell-fate decision system.

    Science.gov (United States)

    Colman-Lerner, Alejandro; Gordon, Andrew; Serra, Eduard; Chin, Tina; Resnekov, Orna; Endy, Drew; Pesce, C Gustavo; Brent, Roger

    2005-09-29

    Here we studied the quantitative behaviour and cell-to-cell variability of a prototypical eukaryotic cell-fate decision system, the mating pheromone response pathway in yeast. We dissected and measured sources of variation in system output, analysing thousands of individual, genetically identical cells. Only a small proportion of total cell-to-cell variation is caused by random fluctuations in gene transcription and translation during the response ('expression noise'). Instead, variation is dominated by differences in the capacity of individual cells to transmit signals through the pathway ('pathway capacity') and to express proteins from genes ('expression capacity'). Cells with high expression capacity express proteins at a higher rate and increase in volume more rapidly. Our results identify two mechanisms that regulate cell-to-cell variation in pathway capacity. First, the MAP kinase Fus3 suppresses variation at high pheromone levels, while the MAP kinase Kss1 enhances variation at low pheromone levels. Second, pathway capacity and expression capacity are negatively correlated, suggesting a compensatory mechanism that allows cells to respond more precisely to pheromone in the presence of a large variation in expression capacity. PMID:16170311

  11. Isolation of mitochondria from CNS

    OpenAIRE

    Kristian, Tibor

    2010-01-01

    This unit contains a protocol describing the isolation of brain mitochondria by using discontinuous Percoll gradient centrifugation. The Percoll density gradient centrifugation separates synaptosomes, myelin, and free non-synaptic mitochondria released from cells during tissue homogenization into individual fractions. Mitochondria entrapped in synaptosomes (synaptic mitochondria) can be liberated using nitrogen cavitation and then further purified by Percoll gradient centrifugation. These met...

  12. Viral infections and cell cycle G2/M regulation

    Institute of Scientific and Technical Information of China (English)

    Richard Y.ZHAO; Robert T.ELDER

    2005-01-01

    Progression of cells from G2 phase of the cell cycle to mitosis is a tightly regulated cellular process that requires activation of the Cdc2 kinase, which determines onset of mitosis in all eukaryotic cells. In both human and fission yeast(Schizosaccharomyces pombe) cells, the activity of Cdc2 is regulated in part by the phosphorylation status of tyrosine 15(Tyr15) on Cdc2, which is phosphorylated by Wee1 kinase during late G2 and is rapidly dephosphorylated by the Cdc25 tyrosine phosphatase to trigger entry into mitosis. These Cdc2 regulators are the downstream targets of two well-characterized G2/M checkpoint pathways which prevent cells from entering mitosis when cellular DNA is damaged or when DNA replication is inhibited. Increasing evidence suggests that Cdc2 is also commonly targeted by viral proteins,which modulate host cell cycle machinery to benefit viral survival or replication. In this review, we describe the effect of viral protein R (Vpr) encoded by human immunodeficiency virus type 1 (HIV-1) on cell cycle G2/M regulation. Based on our current knowledge about this viral effect, we hypothesize that Vpr induces cell cycle G2 arrest through a mechanism that is to some extent different from the classic G2/M checkpoints. One the unique features distinguishing Vpr-induced G2 arrest from the classic checkpoints is the role of phosphatase 2A (PP2A) in Vpr-induced G2 arrest.Interestingly, PP2A is targeted by a number of other viral proteins including SV40 small T antigen, polyomavirus T antigen, HTLV Tax and adenovirus E4orf4. Thus an in-depth understanding of the molecular mechanisms underlying Vpr-induced G2 arrest will provide additional insights into the basic biology of cell cycle G2/M regulation and into the biological significance of this effect during host-pathogen interactions.

  13. Mesenchymal stem cell printing and process regulated cell properties.

    Science.gov (United States)

    Snyder, Jessica; Rin Son, Ae; Hamid, Qudus; Wang, Chengyang; Lui, Yigong; Sun, Wei

    2015-01-01

    This topical review with original analysis and empirical results compares cell sensitivity to physical stress during printing. The objective is to frame a reproducible causation between printing environment and printed cell morphology, viability and phenotype stability. Content includes: (1) a topical review classifies the overlap between physical stress vectors during printing and mesenchymal stem cell sensitivities. (2) Original flow analysis frames the feasible range of stress duration and intensity during manufacturing. (3) Preliminary empirical results define cell properties as a function of minimum, mean and maximum stress conditions. The review and analytical characterization serve as an essential precursor to interpret surprising empirical results. Results identify key cell properties are stress-dependent and controllable based on printing process parameter selection. Printing's minimum stress condition preserves cell viability. The maximum stress increases heterogeneity of cell response, induces inelastic ultra-structural distortion of the cell membrane and chromatin, and increases necrotic subpopulations post-printing. The review, analysis and preliminary results support the feasibility of modulating cell properties during fabrication by prescriptively tuning the stress environment. The process control over cell morphology, health and the rate of differentiation is both a direct result of strain during printing and an in-direct result of increased distress signaling from necrotic sub-populations. PMID:26696405

  14. Stem Cells in the Trabecular Meshwork for Regulating Intraocular Pressure.

    Science.gov (United States)

    Yun, Hongmin; Zhou, Yi; Wills, Andrew; Du, Yiqin

    2016-06-01

    Intraocular pressure (IOP) is still the main treatment target for glaucoma. Outflow resistance mainly exists at the trabecular meshwork (TM) outflow pathway, which is responsible for IOP regulation. Changes of TM cellularity and TM extracellular matrix turnover may play important roles in IOP regulation. In this article, we review basic anatomy and physiology of the outflow pathway and TM stem cell characteristics regarding the location, isolation, identification and function. TM stem cells are localized at the insert region of the TM and are label-retaining in vivo. They can be isolated by side-population cell sorting, cloning culture, or sphere culture. TM stem cells are multipotent with the ability to home to the TM region and differentiate into TM cells in vivo. Other stem cell types, such as adipose-derived stem cells, mesenchymal stem cells and induced pluripotent stem cells have been discovered for TM cell differentiation and TM regeneration. We also review glaucomatous animal models, which are suitable to study stem cell-based therapies for TM regeneration. PMID:27183473

  15. Molecular biological mechanism II. Molecular mechanisms of cell cycle regulation

    International Nuclear Information System (INIS)

    The cell cycle in eukaryotes is regulated by central cell cycle controlling protein kinase complexes. These protein kinase complexes consist of a catalytic subunit from the cyclin-dependent protein kinase family (CDK), and a regulatory subunit from the cyclin family. Cyclins are characterised by their periodic cell cycle related synthesis and destruction. Each cell cycle phase is characterised by a specific set of CDKs and cyclins. The activity of CDK/cyclin complexes is mainly regulated on four levels. It is controlled by specific phosphorylation steps, the synthesis and destruction of cyclins, the binding of specific inhibitor proteins, and by active control of their intracellular localisation. At several critical points within the cell cycle, named checkpoints, the integrity of the cellular genome is monitored. If damage to the genome or an unfinished prior cell cycle phase is detected, the cell cycle progression is stopped. These cell cycle blocks are of great importance to secure survival of cells. Their primary importance is to prevent the manifestation and heritable passage of a mutated genome to daughter cells. Damage sensing, DNA repair, cell cycle control and apoptosis are closely linked cellular defence mechanisms to secure genome integrity. Disregulation in one of these defence mechanisms are potentially correlated with an increased cancer risk and therefore in at least some cases with an increased radiation sensitivity. (orig.)

  16. MHC class II molecules regulate growth in human T cells

    DEFF Research Database (Denmark)

    Nielsen, M; Odum, Niels; Bendtzen, K;

    1994-01-01

    modulate several T cell responses. Here, we studied further the role of class II molecules in the regulation of T cell growth. Costimulation of class II molecules by immobilized HLA-DR mAb significantly enhanced interleukin (IL)-2-supported T cell growth of the majority of CD4+, CD45RAlow, ROhigh T cell......-like) as well as T cells producing both cytokines (THO-like) responded to class II mAb. The costimulatory effect was not restricted to IL-2-driven T cell growth, since TCR/CD3-induced T cell activation was also enhanced by HLA-DR mAb. Moreover, class II costimulation potentiated CD28-mAb-induced T cell...

  17. Transcriptional regulation of dendritic cell diversity.

    Science.gov (United States)

    Chopin, Michaël; Allan, Rhys S; Belz, Gabrielle T

    2012-01-01

    Dendritic cells (DCs) are specialized antigen presenting cells that are exquisitely adapted to sense pathogens and induce the development of adaptive immune responses. They form a complex network of phenotypically and functionally distinct subsets. Within this network, individual DC subsets display highly specific roles in local immunosurveillance, migration, and antigen presentation. This division of labor amongst DCs offers great potential to tune the immune response by harnessing subset-specific attributes of DCs in the clinical setting. Until recently, our understanding of DC subsets has been limited and paralleled by poor clinical translation and efficacy. We have now begun to unravel how different DC subsets develop within a complex multilayered system. These findings open up exciting possibilities for targeted manipulation of DC subsets. Furthermore, ground-breaking developments overcoming a major translational obstacle - identification of similar DC populations in mouse and man - now sets the stage for significant advances in the field. Here we explore the determinants that underpin cellular and transcriptional heterogeneity within the DC network, how these influence DC distribution and localization at steady-state, and the capacity of DCs to present antigens via direct or cross-presentation during pathogen infection.

  18. [Physiological regulation of hematopoietic stem cell and its molecular basis].

    Science.gov (United States)

    Dong, Fang; Hao, Sha; Cheng, Hui; Cheng, Tao

    2016-08-25

    As a classical type of tissue stem cells, hematopoietic stem cell (HSC) is the earliest discovered and has been widely applied in the clinic as a great successful example for stem cell therapy. Thus, HSC research represents a leading field in stem cell biology and regenerative medicine. Self-renewal, differentiation, quiescence, apoptosis and trafficking constitute major characteristics of functional HSCs. These characteristics also signify different dynamic states of HSC through physiological interactions with the microenvironment cues in vivo. This review covers our current knowledge on the physiological regulation of HSC and its underlying molecular mechanisms. It is our hope that this review will not only help our colleagues to understand how HSC is physiologically regulated but also serve as a good reference for the studies on stem cell and regenerative medicine in general. PMID:27546503

  19. CNA/CNS conference summaries

    International Nuclear Information System (INIS)

    This volume contains summaries of papers presented at the 32. annual conference of the Canadian Nuclear Association and the 13. annual conference of the Canadian Nuclear Society. The full proceedings, and the individual papers contained therein, have been abstracted separately. Sessions on the following topics are included: Plenary; The international CANDU program; Canadian used fuel management program; Public information advocates; Fuel and electricity supply; In which direction should reactors advance?; Canadian advanced nuclear research program; International cooperation in operations; Safety in design, operation, regulation; Renovation of operating stations; Reactor physics; New concepts and Technology; Fuel behaviour; Reactor design; Safety analysis; Fuel channel behaviour; Equipment and design qualification; Compliance and licensing; Fusion science and technology; Darlington assessment; Plant aging and life assessment; Thermalhydraulic modelling and analysis; Diagnostics and data management; Operator training and certification

  20. Metallothionein Expression and Roles During Neuropathology in the CNS

    DEFF Research Database (Denmark)

    Penkowa, Milena

    2006-01-01

      This doctoral thesis describes the expression and roles of Metallothioneins I and II (MT-I+II) during CNS pathology. MT-I+II expression increases significantly in reactive astrocytes and microglia/macrophages after traumatic brain injury (cryogenic lesion in cerebral cortex) and brain stem...... scar tissue including revascularization. In the surrounding tissue, MT-I+II stimulate growth cone formation and outgrowths of surviving neurons situated outside the lesioned area; while inside the lesion, normal neurons or neuronal cell bodies were never seen. The angiogenic actions of MT-I+II were...

  1. Regulation of Hedgehog Signalling Inside and Outside the Cell

    Science.gov (United States)

    Ramsbottom, Simon A.; Pownall, Mary E.

    2016-01-01

    The hedgehog (Hh) signalling pathway is conserved throughout metazoans and plays an important regulatory role in both embryonic development and adult homeostasis. Many levels of regulation exist that control the release, reception, and interpretation of the hedgehog signal. The fatty nature of the Shh ligand means that it tends to associate tightly with the cell membrane, and yet it is known to act as a morphogen that diffuses to elicit pattern formation. Heparan sulfate proteoglycans (HSPGs) play a major role in the regulation of Hh distribution outside the cell. Inside the cell, the primary cilium provides an important hub for processing the Hh signal in vertebrates. This review will summarise the current understanding of how the Hh pathway is regulated from ligand production, release, and diffusion, through to signal reception and intracellular transduction.

  2. Huntingtin regulates mammary stem cell division and differentiation.

    Science.gov (United States)

    Elias, Salah; Thion, Morgane S; Yu, Hua; Sousa, Cristovao Marques; Lasgi, Charlène; Morin, Xavier; Humbert, Sandrine

    2014-04-01

    Little is known about the mechanisms of mitotic spindle orientation during mammary gland morphogenesis. Here, we report the presence of huntingtin, the protein mutated in Huntington's disease, in mouse mammary basal and luminal cells throughout mammogenesis. Keratin 5-driven depletion of huntingtin results in a decreased pool and specification of basal and luminal progenitors, and altered mammary morphogenesis. Analysis of mitosis in huntingtin-depleted basal progenitors reveals mitotic spindle misorientation. In mammary cell culture, huntingtin regulates spindle orientation in a dynein-dependent manner. Huntingtin is targeted to spindle poles through its interaction with dynein and promotes the accumulation of NUMA and LGN. Huntingtin is also essential for the cortical localization of dynein, dynactin, NUMA, and LGN by regulating their kinesin 1-dependent trafficking along astral microtubules. We thus suggest that huntingtin is a component of the pathway regulating the orientation of mammary stem cell division, with potential implications for their self-renewal and differentiation properties. PMID:24749073

  3. Huntingtin Regulates Mammary Stem Cell Division and Differentiation

    Directory of Open Access Journals (Sweden)

    Salah Elias

    2014-04-01

    Full Text Available Little is known about the mechanisms of mitotic spindle orientation during mammary gland morphogenesis. Here, we report the presence of huntingtin, the protein mutated in Huntington’s disease, in mouse mammary basal and luminal cells throughout mammogenesis. Keratin 5-driven depletion of huntingtin results in a decreased pool and specification of basal and luminal progenitors, and altered mammary morphogenesis. Analysis of mitosis in huntingtin-depleted basal progenitors reveals mitotic spindle misorientation. In mammary cell culture, huntingtin regulates spindle orientation in a dynein-dependent manner. Huntingtin is targeted to spindle poles through its interaction with dynein and promotes the accumulation of NUMA and LGN. Huntingtin is also essential for the cortical localization of dynein, dynactin, NUMA, and LGN by regulating their kinesin 1-dependent trafficking along astral microtubules. We thus suggest that huntingtin is a component of the pathway regulating the orientation of mammary stem cell division, with potential implications for their self-renewal and differentiation properties.

  4. Regulation of Cell Wall Biogenesis in Saccharomyces cerevisiae: The Cell Wall Integrity Signaling Pathway

    OpenAIRE

    Levin, David E.

    2011-01-01

    The yeast cell wall is a strong, but elastic, structure that is essential not only for the maintenance of cell shape and integrity, but also for progression through the cell cycle. During growth and morphogenesis, and in response to environmental challenges, the cell wall is remodeled in a highly regulated and polarized manner, a process that is principally under the control of the cell wall integrity (CWI) signaling pathway. This pathway transmits wall stress signals from the cell surface to...

  5. Phosphorylation of actopaxin regulates cell spreading and migration

    Science.gov (United States)

    Clarke, Dominic M.; Brown, Michael C.; LaLonde, David P.; Turner, Christopher E.

    2004-01-01

    Actopaxin is an actin and paxillin binding protein that localizes to focal adhesions. It regulates cell spreading and is phosphorylated during mitosis. Herein, we identify a role for actopaxin phosphorylation in cell spreading and migration. Stable clones of U2OS cells expressing actopaxin wild-type (WT), nonphosphorylatable, and phosphomimetic mutants were developed to evaluate actopaxin function. All proteins targeted to focal adhesions, however the nonphosphorylatable mutant inhibited spreading whereas the phosphomimetic mutant cells spread more efficiently than WT cells. Endogenous and WT actopaxin, but not the nonphosphorylatable mutant, were phosphorylated in vivo during cell adhesion/spreading. Expression of the nonphosphorylatable actopaxin mutant significantly reduced cell migration, whereas expression of the phosphomimetic increased cell migration in scrape wound and Boyden chamber migration assays. In vitro kinase assays demonstrate that extracellular signal-regulated protein kinase phosphorylates actopaxin, and treatment of U2OS cells with the MEK1 inhibitor UO126 inhibited adhesion-induced phosphorylation of actopaxin and also inhibited cell migration. PMID:15353548

  6. Transcription factor Nr4a1 couples sympathetic and inflammatory cues in CNS-recruited macrophages to limit neuroinflammation.

    Science.gov (United States)

    Shaked, Iftach; Hanna, Richard N; Shaked, Helena; Chodaczek, Grzegorz; Nowyhed, Heba N; Tweet, George; Tacke, Robert; Basat, Alp Bugra; Mikulski, Zbigniew; Togher, Susan; Miller, Jacqueline; Blatchley, Amy; Salek-Ardakani, Shahram; Darvas, Martin; Kaikkonen, Minna U; Thomas, Graham D; Lai-Wing-Sun, Sonia; Rezk, Ayman; Bar-Or, Amit; Glass, Christopher K; Bandukwala, Hozefa; Hedrick, Catherine C

    2015-12-01

    The molecular mechanisms that link the sympathetic stress response and inflammation remain obscure. Here we found that the transcription factor Nr4a1 regulated the production of norepinephrine (NE) in macrophages and thereby limited experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Lack of Nr4a1 in myeloid cells led to enhanced NE production, accelerated infiltration of leukocytes into the central nervous system (CNS) and disease exacerbation in vivo. In contrast, myeloid-specific deletion of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, protected mice against EAE. Furthermore, we found that Nr4a1 repressed autocrine NE production in macrophages by recruiting the corepressor CoREST to the Th promoter. Our data reveal a new role for macrophages in neuroinflammation and identify Nr4a1 as a key regulator of catecholamine production by macrophages. PMID:26523867

  7. Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) regulate murine neural progenitor cell survival, proliferation, and differentiation.

    Science.gov (United States)

    Scharf, Eugene; May, Victor; Braas, Karen M; Shutz, Kristin C; Mao-Draayer, Yang

    2008-11-01

    Neural stem/progenitor cells (NPC) have gained wide interest over the last decade from their therapeutic potential, either through transplantation or endogenous replacement, after central nervous system (CNS) disease and damage. Whereas several growth factors and cytokines have been shown to promote NPC survival, proliferation, or differentiation, the identification of other regulators will provide much needed options for NPC self-renewal or lineage development. Although previous studies have shown that pituitary adenylate cyclase-activating polypeptide (PACAP)/vasoactive intestinal peptide (VIP) can regulate stem/progenitor cells, the responses appeared variable. To examine the direct roles of these peptides in NPCs, postnatal mouse NPC cultures were withdrawn from epidermal growth factor (EGF) and fibroblastic growth factor (FGF) and maintained under serum-free conditions in the presence or absence of PACAP27, PACAP38, or VIP. The NPCs expressed the PAC1(short)null receptor isoform, and the activation of these receptors decreased progenitor cell apoptosis more than 80% from TUNEL assays and facilitated proliferation more than fivefold from bromodeoxyuridine (BrdU) analyses. To evaluate cellular differentiation, replicate control and peptide-treated cultures were examined for cell fate marker protein and transcript expression. In contrast with previous work, PACAP peptides downregulated NPC differentiation, which appeared consistent with the proliferation status of the treated cells. Accordingly, these results demonstrate that PACAP signaling is trophic and can maintain NPCs in a multipotent state. With these attributes, PACAP may be able to promote endogenous NPC self-renewal in the adult CNS, which may be important for endogenous self-repair in disease and ageing processes.

  8. p53 regulation and activity in mouse embryonic stem cells

    OpenAIRE

    Solozobova, Valeriya

    2010-01-01

    P53 is a tumour development p53. The aim of this work was to study the regulation of p53 in embryonic stem cells and its activation in response to DNA damage. p53 was found that p53 becomes transcriptionally active in ES cells after DNA damage. Embryonic stem cells contain a relatively high amount of p53 protein and p53 RNA. After differentiation p53 level is rapidly downregulated. The high abundance of p53 in undifferentiated ES cells is a result of enhanced translation.

  9. Cell Adhesion and Its Endocytic Regulation in Cell Migration during Neural Development and Cancer Metastasis

    Directory of Open Access Journals (Sweden)

    Takeshi Kawauchi

    2012-04-01

    Full Text Available Cell migration is a crucial event for tissue organization during development, and its dysregulation leads to several diseases, including cancer. Cells exhibit various types of migration, such as single mesenchymal or amoeboid migration, collective migration and scaffold cell-dependent migration. The migration properties are partly dictated by cell adhesion and its endocytic regulation. While an epithelial-mesenchymal transition (EMT-mediated mesenchymal cell migration requires the endocytic recycling of integrin-mediated adhesions after the disruption of cell-cell adhesions, an amoeboid migration is not dependent on any adhesions to extracellular matrix (ECM or neighboring cells. In contrast, a collective migration is mediated by both cell-cell and cell-ECM adhesions, and a scaffold cell-dependent migration is regulated by the endocytosis and recycling of cell-cell adhesion molecules. Although some invasive carcinoma cells exhibit an EMT-mediated mesenchymal or amoeboid migration, other cancer cells are known to maintain cadherin-based cell-cell adhesions and epithelial morphology during metastasis. On the other hand, a scaffold cell-dependent migration is mainly utilized by migrating neurons in normal developing brains. This review will summarize the structures of cell adhesions, including adherens junctions and focal adhesions, and discuss the regulatory mechanisms for the dynamic behavior of cell adhesions by endocytic pathways in cell migration in physiological and pathological conditions, focusing particularly on neural development and cancer metastasis.

  10. Mast Cells Regulate Wound Healing in Diabetes.

    Science.gov (United States)

    Tellechea, Ana; Leal, Ermelindo C; Kafanas, Antonios; Auster, Michael E; Kuchibhotla, Sarada; Ostrovsky, Yana; Tecilazich, Francesco; Baltzis, Dimitrios; Zheng, Yongjun; Carvalho, Eugénia; Zabolotny, Janice M; Weng, Zuyi; Petra, Anastasia; Patel, Arti; Panagiotidou, Smaro; Pradhan-Nabzdyk, Leena; Theoharides, Theoharis C; Veves, Aristidis

    2016-07-01

    Diabetic foot ulceration is a severe complication of diabetes that lacks effective treatment. Mast cells (MCs) contribute to wound healing, but their role in diabetes skin complications is poorly understood. Here we show that the number of degranulated MCs is increased in unwounded forearm and foot skin of patients with diabetes and in unwounded dorsal skin of diabetic mice (P diabetic mice. Pretreatment with the MC degranulation inhibitor disodium cromoglycate rescues diabetes-associated wound-healing impairment in mice and shifts macrophages to the regenerative M2 phenotype (P diabetic mice deficient in MCs have delayed wound healing compared with their wild-type (WT) controls, implying that some MC mediator is needed for proper healing. MCs are a major source of vascular endothelial growth factor (VEGF) in mouse skin, but the level of VEGF is reduced in diabetic mouse skin, and its release from human MCs is reduced in hyperglycemic conditions. Topical treatment with the MC trigger substance P does not affect wound healing in MC-deficient mice, but improves it in WT mice. In conclusion, the presence of nondegranulated MCs in unwounded skin is required for proper wound healing, and therapies inhibiting MC degranulation could improve wound healing in diabetes. PMID:27207516

  11. Physiology and Regulation of Calcium Channels in Stomatal Guard Cells

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Julian I.

    2007-05-02

    Stomatal pores in the epidermis of leaves regulate the diffusion of CO2 into leaves for photosynthetic carbon fixation and control water loss of plants during drought periods. Guard cells sense CO2, water status, light and other environmental conditions to regulate stomatal apertures for optimization of CO2 intake and plant growth under drought stress. The cytosolic second messenger calcium contributes to stomatal movements by transducing signals and regulating ion channels in guard cells. Studies suggest that both plasma membrane Ca2+ influx channels and vacuolar/organellar Ca2+ release channels contribute to ABA-induced Ca2+ elevations in guard cells. Recent research in the P.I.'s laboratory has led to identification of a novel major cation-selective Ca2+-permeable influx channel (Ica) in the plasma membrane of Arabidopsis guard cells. These advances will allow detailed characterization of Ica plasma membrane Ca2+ influx channels in guard cells. The long term goal of this research project is to gain a first detailed characterization of these novel plasma membrane Ca2+-permeable channel currents in Arabidopsis guard cells. The proposed research will investigate the hypothesis that Ica represents an important Ca2+ influx pathway for ABA and CO2 signal transduction in Arabidopsis guard cells. These studies will lead to elucidation of key signal transduction mechanisms by which plants balance CO2 influx into leaves and transpirational water loss and may contribute to future strategies for manipulating gas exchange for improved growth of crop plants and for biomass production.

  12. Id2 regulates hyporesponsive invariant natural killer T cells

    Science.gov (United States)

    Stradner, Martin H; Cheung, Kitty P; Lasorella, Anna; Goldrath, Ananda W; D’Cruz, Louise M

    2016-01-01

    While the invariant natural killer T (iNKT)-cell response to primary stimulation with the glycolipid, α-galactosylceramide (αGalCer), is robust, the secondary response to this stimulus is muted resulting in a hyporesponsive state characterized by anti-inflammatory interleukin-10 (IL-10) production and high expression of programmed cell death 1 (PD1) and neuropilin 1 (NRP1). The E protein transcription factors and their negative regulators, the Id proteins, have previously been shown to regulate iNKT cell thymic development, subset differentiation and peripheral survival. Here, we provide evidence that the expression of the transcriptional regulator Id2 is downregulated upon stimulation of iNKT cells with their cognate antigen. Moreover, loss of Id2 expression by iNKT cells resulted in a hyporesponsive state, with splenic Id2-deficient iNKT cells expressing low levels of TBET, high levels of PD1 and NRP1 and production of IL-10 upon stimulation. We propose that downregulation of Id2 expression is an essential component of induction of the anti-inflammatory, hyporesponsive state in iNKT cells. PMID:26880074

  13. Cell-specific Regulation of APOBEC3F by Interferons

    Institute of Scientific and Technical Information of China (English)

    Songcheng YING; Xuzhao ZHANG; Phuong Thi Nguyen SARKIS; Rongzhen XU; Xiaofang YU

    2007-01-01

    Human cytidine deaminase APOBEC3F (A3F) has broad anti-viral activity against hepatitis B virus and retroviruses including human immunodeficiency virus type 1. However, its regulation in viral natural target cells such CD4+ T lymphocytes, macrophages, and primary liver cells has not been well studied. Here we showed that A3F was up-regulated by interferon (IFN)-α in primary hepatocytes and multiple liver cell lines as well as macrophages. Although the IFN-α signaling pathway was active in T lymphoid cells and induction of other IFN stimulated genes such as PKR was detected, A3F and APOBEC3G (A3G) were not induced by IFN-o in these cells. Thus, additional factors other than known IFN-stimulated genes also regulated IFN-α-induced A3F expression distinctly. A3F and A3G expression levels in primary hepatocytes, especially after IFN-α stimulation, were comparable to those in CD4+ T lymphocytes in some individuals. Significant variations of A3F and A3G expression in primary hepatocytes from various subjects were observed. Individual variations in A3F and/or A3G regulation and expression might influence the clinical outcomes of hepatitis B infection.

  14. Cell volume regulation in epithelial physiology and cancer

    DEFF Research Database (Denmark)

    Pedersen, Stine Helene Falsig; Hoffmann, Else Kay; Novak, Ivana

    2013-01-01

    regulation both rely on the spatially and temporally coordinated function of ion channels and transporters. In healthy epithelia, specific ion channels/transporters localize to the luminal and basolateral membranes, contributing to functional epithelial polarity. In pathophysiological processes...... such as cancer, transepithelial and cell volume regulatory ion transport are dys-regulated. Furthermore, epithelial architecture and coordinated ion transport function are lost, cell survival/death balance is altered, and new interactions with the stroma arise, all contributing to drug resistance. Since altered......The physiological function of epithelia is transport of ions, nutrients, and fluid either in secretory or absorptive direction. All of these processes are closely related to cell volume changes, which are thus an integrated part of epithelial function. Transepithelial transport and cell volume...

  15. Cell fate determination by ubiquitin-dependent regulation of translation

    Science.gov (United States)

    Werner, Achim; Iwasaki, Shintaro; McGourty, Colleen; Medina-Ruiz, Sofia; Teerikorpi, Nia; Fedrigo, Indro; Ingolia, Nicholas T.; Rape, Michael

    2015-01-01

    Metazoan development depends on accurate execution of differentiation programs that allow pluripotent stem cells to adopt specific fates 1. Differentiation requires changes to chromatin architecture and transcriptional networks, yet whether other regulatory events support cell fate determination is less well understood. Here, we have identified the vertebrate-specific ubiquitin ligase CUL3KBTBD8 as an essential regulator of neural crest specification. CUL3KBTBD8 monoubiquitylates NOLC1 and its paralog TCOF1, whose mutation underlies the neurocristopathy Treacher Collins Syndrome 2,3. Ubiquitylation drives formation of a TCOF1-NOLC1 platform that connects RNA polymerase I with ribosome modification enzymes and remodels the translational program of differentiating cells in favor of neural crest specification. We conclude that ubiquitin-dependent regulation of translation is an important feature of cell fate determination. PMID:26399832

  16. Transcriptional Enhancers In The Regulation Of T Cell Differentiation

    OpenAIRE

    Nguyen, Michelle L. T.; Sarah A. Jones; Prier, Julia E.; Brendan Edward Russ

    2015-01-01

    The changes in phenotype and function that characterise the differentiation of naïve T cells to effector and memory states are underscored by large-scale, coordinated, and stable changes in gene expression. In turn, these changes are choreographed by the interplay between transcription factors and epigenetic regulators that act to restructure the genome, ultimately ensuring lineage-appropriate gene expression. Here, we focus on the mechanisms that control T cell differentiation, with a partic...

  17. Bone Cell Autophagy Is Regulated by Environmental Factors

    OpenAIRE

    Zahm, Adam M.; Bohensky, Jolene; Adams, Christopher S.; Shapiro, Irving M.; Srinivas, Vickram

    2011-01-01

    The goal of this investigation was to ascertain whether bone cells undergo autophagy and to determine if this process is regulated by environmental factors. We showed that osteocytes in both murine and human cortical bone display a punctuate distribution of microtubule-associated protein light chain 3, indicative of autophagy. In addition, we noted a basal level of autophagy in preosteocyte-like murine long bone-derived osteocytic (MLO)-A5 cells. Autophagy was upregulated following nutrient d...

  18. Sef Regulates Epithelial-Mesenchymal Transition in Breast Cancer Cells.

    Science.gov (United States)

    He, Qing; Gong, Yan; Gower, Lindsey; Yang, Xuehui; Friesel, Robert E

    2016-10-01

    Sef (similar expression to fgf), also know as IL17RD, is a transmembrane protein shown to inhibit fibroblast growth factor signaling in developmental and cancer contexts; however, its role as a tumor suppressor remains to be fully elucidated. Here, we show that Sef regulates epithelial-mesenchymal transition (EMT) in breast cancer cell lines. Sef expression was highest in the normal breast epithelial cell line MCF10A, intermediate expression in MCF-7 cells and lowest in MDA-MB-231 cells. Knockdown of Sef increased the expression of genes associated with EMT, and promoted cell migration, invasion, and a fibroblastic morphology of MCF-7 cells. Overexpression of Sef inhibited the expression of EMT marker genes and inhibited cell migration and invasion in MCF-7 cells. Induction of EMT in MCF10A cells by TGF-β and TNF-α resulted in downregulation of Sef expression concomitant with upregulation of EMT gene expression and loss of epithelial morphology. Overexpression of Sef in MCF10A cells partially blocked cytokine-induced EMT. Sef was shown to block β-catenin mediated luciferase reporter activity and to cause a decrease in the nuclear localization of active β-catenin. Furthermore, Sef was shown to co-immunoprecipitate with β-catenin. In a mouse orthotopic xenograft model, Sef overexpression in MDA-MB-231 cells slowed tumor growth and reduced expression of EMT marker genes. Together, these data indicate that Sef plays a role in the negative regulation of EMT in a β-catenin dependent manner and that reduced expression of Sef in breast tumor cells may be permissive for EMT and the acquisition of a more metastatic phenotype. J. Cell. Biochem. 117: 2346-2356, 2016. © 2016 Wiley Periodicals, Inc. PMID:26950413

  19. CNS recruitment of CD8+ T lymphocytes specific for a peripheral virus infection triggers neuropathogenesis during polymicrobial challenge.

    Directory of Open Access Journals (Sweden)

    Christine M Matullo

    2011-12-01

    Full Text Available Although viruses have been implicated in central nervous system (CNS diseases of unknown etiology, including multiple sclerosis and amyotrophic lateral sclerosis, the reproducible identification of viral triggers in such diseases has been largely unsuccessful. Here, we explore the hypothesis that viruses need not replicate in the tissue in which they cause disease; specifically, that a peripheral infection might trigger CNS pathology. To test this idea, we utilized a transgenic mouse model in which we found that immune cells responding to a peripheral infection are recruited to the CNS, where they trigger neurological damage. In this model, mice are infected with both CNS-restricted measles virus (MV and peripherally restricted lymphocytic choriomeningitis virus (LCMV. While infection with either virus alone resulted in no illness, infection with both viruses caused disease in all mice, with ∼50% dying following seizures. Co-infection resulted in a 12-fold increase in the number of CD8+ T cells in the brain as compared to MV infection alone. Tetramer analysis revealed that a substantial proportion (>35% of these infiltrating CD8+ lymphocytes were LCMV-specific, despite no detectable LCMV in CNS tissues. Mechanistically, CNS disease was due to edema, induced in a CD8-dependent but perforin-independent manner, and brain herniation, similar to that observed in mice challenged intracerebrally with LCMV. These results indicate that T cell trafficking can be influenced by other ongoing immune challenges, and that CD8+ T cell recruitment to the brain can trigger CNS disease in the apparent absence of cognate antigen. By extrapolation, human CNS diseases of unknown etiology need not be associated with infection with any particular agent; rather, a condition that compromises and activates the blood-brain barrier and adjacent brain parenchyma can render the CNS susceptible to pathogen-independent immune attack.

  20. Host epithelial geometry regulates breast cancer cell invasiveness

    Science.gov (United States)

    Boghaert, Eline; Gleghorn, Jason P.; Lee, KangAe; Gjorevski, Nikolce; Radisky, Derek C.; Nelson, Celeste M.

    2012-01-01

    Breast tumor development is regulated in part by cues from the local microenvironment, including interactions with neighboring nontumor cells as well as the ECM. Studies using homogeneous populations of breast cancer cell lines cultured in 3D ECM have shown that increased ECM stiffness stimulates tumor cell invasion. However, at early stages of breast cancer development, malignant cells are surrounded by normal epithelial cells, which have been shown to exert a tumor-suppressive effect on cocultured cancer cells. Here we explored how the biophysical characteristics of the host microenvironment affect the proliferative and invasive tumor phenotype of the earliest stages of tumor development, by using a 3D microfabrication-based approach to engineer ducts composed of normal mammary epithelial cells that contained a single tumor cell. We found that the phenotype of the tumor cell was dictated by its position in the duct: proliferation and invasion were enhanced at the ends and blocked when the tumor cell was located elsewhere within the tissue. Regions of invasion correlated with high endogenous mechanical stress, as shown by finite element modeling and bead displacement experiments, and modulating the contractility of the host epithelium controlled the subsequent invasion of tumor cells. Combining microcomputed tomographic analysis with finite element modeling suggested that predicted regions of high mechanical stress correspond to regions of tumor formation in vivo. This work suggests that the mechanical tone of nontumorigenic host epithelium directs the phenotype of tumor cells and provides additional insight into the instructive role of the mechanical tumor microenvironment. PMID:23150585

  1. NK Cell Subtypes as Regulators of Autoimmune Liver Disease

    Science.gov (United States)

    2016-01-01

    As major components of innate immunity, NK cells not only exert cell-mediated cytotoxicity to destroy tumors or infected cells, but also act to regulate the functions of other cells in the immune system by secreting cytokines and chemokines. Thus, NK cells provide surveillance in the early defense against viruses, intracellular bacteria, and cancer cells. However, the effecter function of NK cells must be exquisitely controlled to prevent inadvertent attack against normal “self” cells. In an organ such as the liver, where the distinction between immunotolerance and immune defense against routinely processed pathogens is critical, the plethora of NK cells has a unique role in the maintenance of homeostasis. Once self-tolerance is broken, autoimmune liver disease resulted. NK cells act as a “two-edged weapon” and even play opposite roles with both regulatory and inducer activities in the hepatic environment. That is, NK cells act not only to produce inflammatory cytokines and chemokines, but also to alter the proliferation and activation of associated lymphocytes. However, the precise regulatory mechanisms at work in autoimmune liver diseases remain to be identified. In this review, we focus on recent research with NK cells and their potential role in the development of autoimmune liver disease. PMID:27462349

  2. Controlling the switches: Rho GTPase regulation during animal cell mitosis.

    Science.gov (United States)

    Zuo, Yan; Oh, Wonkyung; Frost, Jeffrey A

    2014-12-01

    Animal cell division is a fundamental process that requires complex changes in cytoskeletal organization and function. Aberrant cell division often has disastrous consequences for the cell and can lead to cell senescence, neoplastic transformation or death. As important regulators of the actin cytoskeleton, Rho GTPases play major roles in regulating many aspects of mitosis and cytokinesis. These include centrosome duplication and separation, generation of cortical rigidity, microtubule-kinetochore stabilization, cleavage furrow formation, contractile ring formation and constriction, and abscission. The ability of Rho proteins to function as regulators of cell division depends on their ability to cycle between their active, GTP-bound and inactive, GDP-bound states. However, Rho proteins are inherently inefficient at fulfilling this cycle and require the actions of regulatory proteins that enhance GTP binding (RhoGEFs), stimulate GTPase activity (RhoGAPs), and sequester inactive Rho proteins in the cytosol (RhoGDIs). The roles of these regulatory proteins in controlling cell division are an area of active investigation. In this review we will delineate the current state of knowledge of how specific RhoGEFs, RhoGAPs and RhoGDIs control mitosis and cytokinesis, and highlight the mechanisms by which their functions are controlled.

  3. Phosphorylation of Large T Antigen Regulates Merkel Cell Polyomavirus Replication

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Jason; Wang, Xin; Tsang, Sabrina H. [Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 (United States); Jiao, Jing [Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 (United States); You, Jianxin, E-mail: jianyou@mail.med.upenn.edu [Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 (United States)

    2014-07-08

    Merkel Cell Polyomavirus (MCPyV) was recently discovered as a novel human polyomavirus that is associated with ~80% of Merkel Cell Carcinomas. The Large Tumor antigen (LT) is an early viral protein which has a variety of functions, including manipulation of the cell cycle and initiating viral DNA replication. Phosphorylation plays a critical regulatory role for polyomavirus LT proteins, but no investigation of MCPyV LT phosphorylation has been performed to date. In this report mass spectrometry analysis reveals three unique phosphorylation sites: T271, T297 and T299. In vivo replication assays confirm that phosphorylation of T271 does not play a role in viral replication, while modification at T297 and T299 have dramatic and opposing effects on LT’s ability to initiate replication from the viral origin. We test these mutants for their ability to bind, unwind, and act as a functional helicase at the viral origin. These studies provide a framework for understanding how phosphorylation of LT may dynamically regulate viral replication. Although the natural host cell of MCPyV has not yet been established, this work provides a foundation for understanding how LT activity is regulated and provides tools for better exploring this regulation in both natural host cells and Merkel cells.

  4. Regulation of cell division in higher plants. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, T.W.

    1992-07-01

    Cell division is arguably the most fundamental of all developmental processes. In higher plants, mitotic activity is largely confined to foci of patterned cell divisions called meristems. From these perpetually embryonic tissues arise the plant`s essential organs of light capture, support, protection and reproduction. Once an adequate understanding of plant cell mitotic regulation is attained, unprecedented opportunities will ensue for analyzing and genetically controlling diverse aspects of development, including plant architecture, leaf shape, plant height, and root depth. The mitotic cycle in a variety of model eukaryotic systems in under the control of a regulatory network of striking evolutionary conservation. Homologues of the yeast cdc2 gene, its catalytic product, p34, and the cyclin regulatory subunits of the MPF complex have emerged as ubiquitous mitotic regulators. We have cloned cdc2-like and cyclin genes from pea. As in other eukaryotic model systems, p34 of Pisum sativum is a subunit of a high molecular weight complex which binds the fission yeast p13 protein and displays histone H1 kinase activity in vitro. Our primary objective in this study is to gain baseline information about the regulation of this higher plant cell division control complex in non-dividing, differentiated cells as well as in synchronous and asynchronous mitotic cells. We are investigating cdc2 and cyclin expression at the levels of protein abundance, protein phosphorylation and quaternary associations.

  5. NSA2, a novel nucleolus protein regulates cell proliferation and cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Heyu [Department of Immunology, School of Basic Medical Sciences, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China); Human Disease Genomics Center, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China); Ma, Xi [Department of Immunology, School of Basic Medical Sciences, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China); Human Disease Genomics Center, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China); State Key Lab of Animal Nutrition, China Agricultural University, No. 2 Yuanmingyuan West Road, Beijing 100193 (China); Shi, Taiping [Chinese National Human Genome Center, Beijing. 3-707 North YongChang Road BDA, Beijing 100176 (China); Song, Quansheng [Department of Immunology, School of Basic Medical Sciences, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China); Human Disease Genomics Center, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China); Zhao, Hongshan, E-mail: hongshan@bjmu.edu.cn [Department of Immunology, School of Basic Medical Sciences, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China); Human Disease Genomics Center, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China); Ma, Dalong [Department of Immunology, School of Basic Medical Sciences, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China); Human Disease Genomics Center, Peking University, No. 38 Xueyuan Road, Beijing 100191 (China)

    2010-01-01

    NSA2 (Nop seven-associated 2) was previously identified in a high throughput screen of novel human genes associated with cell proliferation, and the NSA2 protein is evolutionarily conserved across different species. In this study, we revealed that NSA2 is broadly expressed in human tissues and cultured cell lines, and located in the nucleolus of the cell. Both of the putative nuclear localization signals (NLSs) of NSA2, also overlapped with nucleolar localization signals (NoLSs), are capable of directing nucleolar accumulation. Moreover, over-expression of the NSA2 protein promoted cell growth in different cell lines and regulated the G1/S transition in the cell cycle. SiRNA silencing of the NSA2 transcript attenuated the cell growth and dramatically blocked the cell cycle in G1/S transition. Our results demonstrated that NSA2 is a nucleolar protein involved in cell proliferation and cell cycle regulation.

  6. Modulation of junction tension by tumor suppressors and proto-oncogenes regulates cell-cell contacts.

    Science.gov (United States)

    Bosveld, Floris; Guirao, Boris; Wang, Zhimin; Rivière, Mathieu; Bonnet, Isabelle; Graner, François; Bellaïche, Yohanns

    2016-02-15

    Tumor suppressors and proto-oncogenes play crucial roles in tissue proliferation. Furthermore, de-regulation of their functions is deleterious to tissue architecture and can result in the sorting of somatic rounded clones minimizing their contact with surrounding wild-type (wt) cells. Defects in the shape of somatic clones correlate with defects in proliferation, cell affinity, cell-cell adhesion, oriented cell division and cortical contractility. Combining genetics, live-imaging, laser ablation and computer simulations, we aim to analyze whether distinct or similar mechanisms can account for the common role of tumor suppressors and proto-oncogenes in cell-cell contact regulation. In Drosophila epithelia, the tumor suppressors Fat (Ft) and Dachsous (Ds) regulate cell proliferation, tissue morphogenesis, planar cell polarity and junction tension. By analyzing the evolution over time of ft mutant cells and clones, we show that ft clones reduce their cell-cell contacts with the surrounding wt tissue in the absence of concomitant cell divisions and over-proliferation. This contact reduction depends on opposed changes of junction tensions in the clone bulk and its boundary with neighboring wt tissue. More generally, either clone bulk or boundary junction tension is modulated by the activation of Yorkie, Myc and Ras, yielding similar contact reductions with wt cells. Together, our data highlight mechanical roles for proto-oncogene and tumor suppressor pathways in cell-cell interactions.

  7. Regulated growth of diatom cells on self-assembled monolayers

    Directory of Open Access Journals (Sweden)

    Kobayashi Koichi

    2007-03-01

    Full Text Available Abstract We succeeded in regulating the growth of diatom cells on chemically modified glass surfaces. Glass surfaces were functionalized with -CF3, -CH3, -COOH, and -NH2 groups using the technique of self-assembled monolayers (SAM, and diatom cells were subsequently cultured on these surfaces. When the samples were rinsed after the adhesion of the diatom cells on the modified surfaces, the diatoms formed two dimensional arrays; this was not possible without the rinsing treatment. Furthermore, we examined the number of cells that grew and their motility by time-lapse imaging in order to clarify the interaction between the cells and SAMs. We hope that our results will be a basis for developing biodevices using living photosynthetic diatom cells.

  8. Regulation of stem cells in the zebra fish hematopoietic system.

    Science.gov (United States)

    Huang, H-T; Zon, L I

    2008-01-01

    Hematopoietic stem cells (HSCs) have been used extensively as a model for stem cell biology. Stem cells share the ability to self-renew and differentiate into multiple cell types, making them ideal candidates for tissue regeneration or replacement therapies. Current applications of stem cell technology are limited by our knowledge of the molecular mechanisms that control their proliferation and differentiation, and various model organisms have been used to fill these gaps. This chapter focuses on the contributions of the zebra fish model to our understanding of stem cell regulation within the hematopoietic system. Studies in zebra fish have been valuable for identifying new genetic and signaling factors that affect HSC formation and development with important implications for humans, and new advances in the zebra fish toolbox will allow other aspects of HSC behavior to be investigated as well, including migration, homing, and engraftment.

  9. Mechanism of regulation of stem cell differentiation by matrix stiffness.

    Science.gov (United States)

    Lv, Hongwei; Li, Lisha; Sun, Meiyu; Zhang, Yin; Chen, Li; Rong, Yue; Li, Yulin

    2015-05-27

    Stem cell behaviors are regulated by multiple microenvironmental cues. As an external signal, mechanical stiffness of the extracellular matrix is capable of governing stem cell fate determination, but how this biophysical cue is translated into intracellular signaling remains elusive. Here, we elucidate mechanisms by which stem cells respond to microenvironmental stiffness through the dynamics of the cytoskeletal network, leading to changes in gene expression via biophysical transduction signaling pathways in two-dimensional culture. Furthermore, a putative rapid shift from original mechanosensing to de novo cell-derived matrix sensing in more physiologically relevant three-dimensional culture is pointed out. A comprehensive understanding of stem cell responses to this stimulus is essential for designing biomaterials that mimic the physiological environment and advancing stem cell-based clinical applications for tissue engineering.

  10. Regulative Function of Telomerase and Extracelluar Regulated Protein Kinases to Leukemic Cell Apoptosis

    Institute of Scientific and Technical Information of China (English)

    李登举; 张瑶珍; 曹文静; 孙岚; 徐慧珍; 路武

    2002-01-01

    Summary: In order to investigate the regulative function of telomerase and phosphorylated (acti-vated) extracelluar regulated protein kinase (ERK) i and 2 in the leukemic cell lines HL-60 andK562 proliferation inhibition and apoptosis, three chemotherapeutic drugs Harringtonine (HRT),Vincristine(VCR)and Etoposide(Vp16)were selected as inducers. The proliferation inhibition ratewas detected by MTT method, the cell cycle and cell apoptosis was analyzed by flow cytometryand the telomerase activity was detected by the telomeric repeat amplification protocol (TRAP)assay and bioluminescence analysis method. The phosphorylated ERK1/2 protein expression wasdetected by western blot method. The results showed that HRT, VCR and Vp16 could inhibit cellproliferation, induce apoptosis, inhibit telomerase activity and down-regulate the protein expres-sion of phosphorylated ERK. It was suggested that ERK signal transduction pathway was involvedin the down-regulation of telomerase activity and the onset of apoptosis in the leukemic cells treat-ed by HRT, VCR and Vp16.

  11. Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for molecules associated with metabolism, signaling and regulation in central nervous system mixed glial cell cultures

    Directory of Open Access Journals (Sweden)

    Studzinski Diane

    2009-01-01

    Full Text Available Abstract Background Cytokines secreted by immune cells and activated glia play central roles in both the pathogenesis of and protection from damage to the central nervous system (CNS in multiple sclerosis (MS. Methods We have used gene array analysis to identify the initial direct effects of cytokines on CNS glia by comparing changes in early gene expression in CNS glial cultures treated for 6 hours with cytokines typical of those secreted by Th1 and Th2 lymphocytes and monocyte/macrophages (M/M. Results In two previous papers, we summarized effects of these cytokines on immune-related molecules, and on neural and glial related proteins, including neurotrophins, growth factors and structural proteins. In this paper, we present the effects of the cytokines on molecules involved in metabolism, signaling and regulatory mechanisms in CNS glia. Many of the changes in gene expression were similar to those seen in ischemic preconditioning and in early inflammatory lesions in experimental autoimmune encephalomyelitis (EAE, related to ion homeostasis, mitochondrial function, neurotransmission, vitamin D metabolism and a variety of transcription factors and signaling pathways. Among the most prominent changes, all three cytokine mixtures markedly downregulated the dopamine D3 receptor, while Th1 and Th2 cytokines downregulated neuropeptide Y receptor 5. An unexpected finding was the large number of changes related to lipid metabolism, including several suggesting a switch from diacylglycerol to phosphatidyl inositol mediated signaling pathways. Using QRT-PCR we validated the results for regulation of genes for iNOS, arginase and P glycoprotein/multi-drug resistance protein 1 (MDR1 seen at 6 hours with microarray. Conclusion Each of the three cytokine mixtures differentially regulated gene expression related to metabolism and signaling that may play roles in the pathogenesis of MS, most notably with regard to mitochondrial function and neurotransmitter

  12. Investigating Microenvironmental Regulation of Human Chordoma Cell Behaviour

    Science.gov (United States)

    Patel, Priya; Brooks, Courtney; Seneviratne, Ayesh; Hess, David A.; Séguin, Cheryle A.

    2014-01-01

    The tumour microenvironment is complex and composed of many different constituents, including matricellular proteins such as connective tissue growth factor (CCN2), and is characterized by gradients in oxygen levels. In various cancers, hypoxia and CCN2 promote stem and progenitor cell properties, and regulate the proliferation, migration and phenotype of cancer cells. Our study was aimed at investigating the effects of hypoxia and CCN2 on chordoma cells, using the human U-CH1 cell line. We demonstrate that under basal conditions, U-CH1 cells express multiple CCN family members including CCN1, CCN2, CCN3 and CCN5. Culture of U-CH1 cells in either hypoxia or in the presence of recombinant CCN2 peptide promoted progenitor cell-like characteristics specific to the notochordal tissue of origin. Specifically, hypoxia induced the most robust increase in progenitor-like characteristics in U-CH1 cells, including increased expression of the notochord-associated markers T, CD24, FOXA1, ACAN and CA12, increased cell growth and tumour-sphere formation, and a decrease in the percentage of vacuolated cells present in the heterogeneous population. Interestingly, the effects of recombinant CCN2 peptide on U-CH1 cells were more pronounced under normoxia than hypoxia, promoting increased expression of CCN1, CCN2, CCN3 and CCN5, the notochord-associated markers SOX5, SOX6, T, CD24, and FOXA1 as well as increased tumour-sphere formation. Overall, this study highlights the importance of multiple factors within the tumour microenvironment and how hypoxia and CCN2 may regulate human chordoma cell behaviour. PMID:25541962

  13. Investigating microenvironmental regulation of human chordoma cell behaviour.

    Directory of Open Access Journals (Sweden)

    Priya Patel

    Full Text Available The tumour microenvironment is complex and composed of many different constituents, including matricellular proteins such as connective tissue growth factor (CCN2, and is characterized by gradients in oxygen levels. In various cancers, hypoxia and CCN2 promote stem and progenitor cell properties, and regulate the proliferation, migration and phenotype of cancer cells. Our study was aimed at investigating the effects of hypoxia and CCN2 on chordoma cells, using the human U-CH1 cell line. We demonstrate that under basal conditions, U-CH1 cells express multiple CCN family members including CCN1, CCN2, CCN3 and CCN5. Culture of U-CH1 cells in either hypoxia or in the presence of recombinant CCN2 peptide promoted progenitor cell-like characteristics specific to the notochordal tissue of origin. Specifically, hypoxia induced the most robust increase in progenitor-like characteristics in U-CH1 cells, including increased expression of the notochord-associated markers T, CD24, FOXA1, ACAN and CA12, increased cell growth and tumour-sphere formation, and a decrease in the percentage of vacuolated cells present in the heterogeneous population. Interestingly, the effects of recombinant CCN2 peptide on U-CH1 cells were more pronounced under normoxia than hypoxia, promoting increased expression of CCN1, CCN2, CCN3 and CCN5, the notochord-associated markers SOX5, SOX6, T, CD24, and FOXA1 as well as increased tumour-sphere formation. Overall, this study highlights the importance of multiple factors within the tumour microenvironment and how hypoxia and CCN2 may regulate human chordoma cell behaviour.

  14. B Cells Regulate CD4+ T cell Responses to Papain Following BCR-Independent Papain Uptake

    OpenAIRE

    Dwyer, Daniel F.; Woodruff, Matthew C.; Carroll, Michael C.; Austen, K. Frank; Gurish, Michael F.

    2014-01-01

    Papain, a cysteine protease allergen with inherent adjuvant activity, induces potent IL4 expression by T cells in the popliteal lymph nodes (PLN) of mice following footpad immunization. Here we identify a novel, non-BCR mediated capacity for B cells to rapidly bind and internalize papain. B cells subsequently regulate the adaptive immune response by enhancing Inducible T cell Costimulator (ICOS) expression on CD4+ T cells and amplifying Th2 and T follicular helper induction. Antibody blockade...

  15. Retinoic acid signalling in thymocytes regulates T cell development

    DEFF Research Database (Denmark)

    Wendland, Kerstin; Sitnik, Katarzyna Maria; Kotarsky, Knut;

    The Vitamin A derivative retinoic acid (RA) has emerged as an important regulator of peripheral T cell responses. However, whether there is endogenous retinoic acid receptor (RAR) signaling in developing thymocytes and the potential impact of such signals in thymocyte development remains unclear...

  16. Isolation, characterization, and molecular regulation of muscle stem cells

    Directory of Open Access Journals (Sweden)

    So-ichiro eFukada

    2013-11-01

    Full Text Available keletal muscle has great regenerative capacity which is dependent on muscle stem cells, also known as satellite cells. A loss of satellite cells and/or their function impairs skeletal muscle regeneration and leads to a loss of skeletal muscle power; therefore, the molecular mechanisms for maintaining satellite cells in a quiescent and undifferentiated state are of great interest in skeletal muscle biology. Many studies have demonstrated proteins expressed by satellite cells, including Pax7, M-cadherin, Cxcr4, syndecan3/4, and c-met. To further characterize satellite cells, we established a method to directly isolate satellite cells using a monoclonal antibody, SM/C-2.6. Using SM/C-2.6 and microarrays, we measured the genes expressed in quiescent satellite cells and demonstrated that Hesr3 may complement Hesr1 in generating quiescent satellite cells. Although Hesr1- or Hesr3-single knockout mice show a normal skeletal muscle phenotype, including satellite cells, Hesr1/Hesr3-double knockout mice show a gradual decrease in the number of satellite cells and increase in regenerative defects dependent on satellite cell numbers. We also observed that a mouse’s genetic background affects the regenerative capacity of its skeletal muscle and have established a line of DBA/2-background mdx mice that has a much more severe phenotype than the frequently used C57BL/10-mdx mice. The phenotype of DBA/2-mdx mice also seems to depend on the function of satellite cells. In this review, we summarize the methodology of direct isolation, characterization, and molecular regulation of satellite cells based on our results. The relationship between the regenerative capacity of satellite cells and progression of muscular disorders is also summarized. In the last part, we discuss application of the accumulating scientific information on satellite cells to treatment of patients with muscular disorders.

  17. Disruption of Iron Regulation after Radiation and Donor Cell Infusion.

    Science.gov (United States)

    Karoopongse, Ekapun; Marcondes, A Mario; Yeung, Cecilia; Holman, Zaneta; Kowdley, Kris V; Campbell, Jean S; Deeg, H Joachim

    2016-07-01

    Iron overload is common in patients undergoing hematopoietic cell transplantation (HCT). Peritransplant events, such as total body irradiation (TBI), and the effects of donor cell infusion may contribute to iron overload, in addition to disease-associated anemia and RBC transfusions. Using murine models we show complex time- and dose-dependent interactions of TBI and transplanted donor cells with expression patterns of iron regulatory genes in the liver. Infusion of allogeneic or syngeneic donor T lymphocytes increased serum iron, transiently up-regulated interleukin-6 (IL-6) and hepcidin (Hamp), and down-regulated ferroportin1 (Fpn1). After 7 to 14 days, however, changes were significant only with allogeneic cells. TBI (200 to 400 Gy) also induced IL-6 and Hamp expression but had little effect on Fpn1. TBI combined with allogeneic donor cell infusion resulted in modest early up-regulation of IL-6, followed by a decline in IL-6 levels and Hamp as well as Fpn1, and was accompanied by increased liver iron content. Injection of Fas ligand-deficient T lymphocytes from gld mice resulted in substantially lower alterations of gene expression than infusion of wild-type T cells. The agonistic anti-Fas antibody, JO2, triggered early up-regulation of Stat3 and IL-6, followed by an increase in Hamp and decreased expression of Fpn1 by 7 to 14 days, implicating Fas as a key modulator of gene expression in HCT. Minimal histologic changes were observed in mouse liver and duodenum. These data show profound and interacting effects of TBI and cell transplantation on the expression of iron regulatory genes in murine recipients. Alterations are largely related to induction of cytokines and Fas-dependent signals. PMID:27060441

  18. Identification of a novel intronic enhancer responsible for the transcriptional regulation of musashi1 in neural stem/progenitor cells

    Directory of Open Access Journals (Sweden)

    Kawase Satoshi

    2011-04-01

    Full Text Available Abstract Background The specific genetic regulation of neural primordial cell determination is of great interest in stem cell biology. The Musashi1 (Msi1 protein, which belongs to an evolutionarily conserved family of RNA-binding proteins, is a marker for neural stem/progenitor cells (NS/PCs in the embryonic and post-natal central nervous system (CNS. Msi1 regulates the translation of its downstream targets, including m-Numb and p21 mRNAs. In vitro experiments using knockout mice have shown that Msi1 and its isoform Musashi2 (Msi2 keep NS/PCs in an undifferentiated and proliferative state. Msi1 is expressed not only in NS/PCs, but also in other somatic stem cells and in tumours. Based on previous findings, Msi1 is likely to be a key regulator for maintaining the characteristics of self-renewing stem cells. However, the mechanisms regulating Msi1 expression are not yet clear. Results To identify the DNA region affecting Msi1 transcription, we inserted the fusion gene ffLuc, comprised of the fluorescent Venus protein and firefly Luciferase, at the translation initiation site of the mouse Msi1 gene locus contained in a 184-kb bacterial artificial chromosome (BAC. Fluorescence and Luciferase activity, reflecting the Msi1 transcriptional activity, were observed in a stable BAC-carrying embryonic stem cell line when it was induced toward neural lineage differentiation by retinoic acid treatment. When neuronal differentiation was induced in embryoid body (EB-derived neurosphere cells, reporter signals were detected in Msi1-positive NSCs and GFAP-positive astrocytes, but not in MAP2-positive neurons. By introducing deletions into the BAC reporter gene and conducting further reporter experiments using a minimized enhancer region, we identified a region, "D5E2," that is responsible for Msi1 transcription in NS/PCs. Conclusions A regulatory element for Msi1 transcription in NS/PCs is located in the sixth intron of the Msi1 gene. The 595-bp D5E2 intronic

  19. VMP1 related autophagy and apoptosis in colorectal cancer cells: VMP1 regulates cell death

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Qinyi [Department of Ultrasonograph, Changshu No. 2 People’s Hospital, Changshu (China); Zhou, Hao; Chen, Yan [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China); Shen, Chenglong [Department of General Surgery, Changshu No. 2 People’s Hospital, Changshu (China); He, Songbing; Zhao, Hua; Wang, Liang [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China); Wan, Daiwei, E-mail: 372710369@qq.com [Department of Hepatobiliary Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou (China); Gu, Wen, E-mail: 505339704@qq.com [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China)

    2014-01-17

    Highlights: •This research confirmed VMP1 as a regulator of autophagy in colorectal cancer cell lines. •We proved the pro-survival role of VMP1-mediated autophagy in colorectal cancer cell lines. •We found the interaction between VMP1 and BECLIN1 also existing in colorectal cancer cell lines. -- Abstract: Vacuole membrane protein 1 (VMP1) is an autophagy-related protein and identified as a key regulator of autophagy in recent years. In pancreatic cell lines, VMP1-dependent autophagy has been linked to positive regulation of apoptosis. However, there are no published reports on the role of VMP1 in autophagy and apoptosis in colorectal cancers. Therefore, to address this gap of knowledge, we decided to interrogate regulation of autophagy and apoptosis by VMP1. We have studied the induction of autophagy by starvation and rapamycin treatment in colorectal cell lines using electron microscopy, immunofluorescence, and immunoblotting. We found that starvation-induced autophagy correlated with an increase in VMP1 expression, that VMP1 interacted with BECLIN1, and that siRNA mediated down-regulation of VMP1-reduced autophagy. Next, we examined the relationship between VMP1-dependent autophagy and apoptosis and found that VMP1 down-regulation sensitizes cells to apoptosis and that agents that induce apoptosis down-regulate VMP1. In conclusion, similar to its reported role in other cell types, VMP1 is an important regulator of autophagy in colorectal cell lines. However, in contrast to its role in pancreatic cell lines, in colorectal cancer cells, VMP1-dependent autophagy appears to be pro-survival rather than pro-cell death.

  20. Purinergic Signaling as a Regulator of Th17 Cell Plasticity.

    Directory of Open Access Journals (Sweden)

    Dominique Fernández

    Full Text Available T helper type 17 (Th17 lymphocytes, characterized by the production of interleukin-17 and other pro-inflammatory cytokines, are present in intestinal lamina propria and have been described as important players driving intestinal inflammation. Recent evidence, supporting the notion of a functional and phenotypic instability of Th17 cells, has shown that Th17 differentiate into type 1 regulatory (Tr1 T cells during the resolution of intestinal inflammation. Moreover, it has been suggested that the expression of CD39 ectonucleotidase endows Th17 cells with immunosuppressive properties. However, the exact role of CD39 ectonucleotidase in Th17 cells has not been studied in the context of intestinal inflammation. Here we show that Th17 cells expressing CD39 ectonucleotidase can hydrolyze ATP and survive to ATP-induced cell death. Moreover, in vitro-generated Th17 cells expressing the CD39 ectonucleotidase produce IL-10 and are less pathogenic than CD39 negative Th17 cells in a model of experimental colitis in Rag-/- mice. Remarkably, we show that CD39 activity regulates the conversion of Th17 cells to IL-10-producing cells in vitro, which is abrogated in the presence of ATP and the CD39-specific inhibitor ARL67156. All these data suggest that CD39 expression by Th17 cells allows the depletion of ATP and is crucial for IL-10 production and survival during the resolution of intestinal inflammation.

  1. Purinergic Signaling as a Regulator of Th17 Cell Plasticity

    Science.gov (United States)

    Fernández, Dominique; Flores-Santibáñez, Felipe; Neira, Jocelyn; Osorio-Barrios, Francisco; Tejón, Gabriela; Nuñez, Sarah; Hidalgo, Yessia; Fuenzalida, Maria Jose; Meza, Daniel; Ureta, Gonzalo; Lladser, Alvaro; Pacheco, Rodrigo; Acuña-Castillo, Claudio; Guixé, Victoria; Quintana, Francisco J.; Bono, Maria Rosa; Rosemblatt, Mario; Sauma, Daniela

    2016-01-01

    T helper type 17 (Th17) lymphocytes, characterized by the production of interleukin-17 and other pro-inflammatory cytokines, are present in intestinal lamina propria and have been described as important players driving intestinal inflammation. Recent evidence, supporting the notion of a functional and phenotypic instability of Th17 cells, has shown that Th17 differentiate into type 1 regulatory (Tr1) T cells during the resolution of intestinal inflammation. Moreover, it has been suggested that the expression of CD39 ectonucleotidase endows Th17 cells with immunosuppressive properties. However, the exact role of CD39 ectonucleotidase in Th17 cells has not been studied in the context of intestinal inflammation. Here we show that Th17 cells expressing CD39 ectonucleotidase can hydrolyze ATP and survive to ATP-induced cell death. Moreover, in vitro-generated Th17 cells expressing the CD39 ectonucleotidase produce IL-10 and are less pathogenic than CD39 negative Th17 cells in a model of experimental colitis in Rag-/- mice. Remarkably, we show that CD39 activity regulates the conversion of Th17 cells to IL-10-producing cells in vitro, which is abrogated in the presence of ATP and the CD39-specific inhibitor ARL67156. All these data suggest that CD39 expression by Th17 cells allows the depletion of ATP and is crucial for IL-10 production and survival during the resolution of intestinal inflammation. PMID:27322617

  2. Putting On The Breaks: Regulating Organelle Movements in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Julianna K.Vick; Andreas Nebenführ

    2012-01-01

    A striking characteristic of plant cells is that their organelles can move rapidly through the cell.This movement,commonly referred to as cytoplasmic streaming,has been observed for over 200 years,but we are only now beginning to decipher the mechanisms responsible for it.The identification of the myosin motor proteins responsible for these movements allows us to probe the regulatory events that coordinate organelle displacement with normal cell physiology.This review will highlight several recent developments that have provided new insight into the regulation of organelle movement,both at the cellular level and at the molecular level.

  3. System x(c)(-) regulates microglia and macrophage glutamate excitotoxicity in vivo.

    Science.gov (United States)

    Kigerl, Kristina A; Ankeny, Daniel P; Garg, Sanjay K; Wei, Ping; Guan, Zhen; Lai, Wenmin; McTigue, Dana M; Banerjee, Ruma; Popovich, Phillip G

    2012-01-01

    It is widely believed that microglia and monocyte-derived macrophages (collectively referred to as central nervous system (CNS) macrophages) cause excitotoxicity in the diseased or injured CNS. This view has evolved mostly from in vitro studies showing that neurotoxic concentrations of glutamate are released from CNS macrophages stimulated with lipopolysaccharide (LPS), a potent inflammogen. We hypothesized that excitotoxic killing by CNS macrophages is more rigorously controlled in vivo, requiring both the activation of the glutamate/cystine antiporter (system x(c)(-)) and an increase in extracellular cystine, the substrate that drives glutamate release. Here, we show that non-traumatic microinjection of low-dose LPS into spinal cord gray matter activates CNS macrophages but without causing overt neuropathology. In contrast, neurotoxic inflammation occurs when LPS and cystine are co-injected. Simultaneous injection of NBQX, an antagonist of AMPA glutamate receptors, reduces the neurotoxic effects of LPS+cystine, implicating glutamate as a mediator of neuronal cell death in this model. Surprisingly, neither LPS nor LPS+cystine adversely affects survival of oligodendrocytes or oligodendrocyte progenitor cells. Ex vivo analyses show that redox balance in microglia and macrophages is controlled by induction of system x(c)(-) and that high GSH:GSSG ratios predict the neurotoxic potential of these cells. Together, these data indicate that modulation of redox balance in CNS macrophages, perhaps through regulating system x(c)(-), could be a novel approach for attenuating injurious neuroinflammatory cascades.

  4. CNS effects following the treatment of malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Rane, N., E-mail: rane@cantab.net [Department of Neuroradiology, The West Wing, John Radcliffe Hospital, Oxford Radcliffe NHS Trust, Oxford (United Kingdom); Quaghebeur, G. [Department of Neuroradiology, The West Wing, John Radcliffe Hospital, Oxford Radcliffe NHS Trust, Oxford (United Kingdom)

    2012-01-15

    Corporeal and central nervous system (CNS) axis chemotherapy and radiotherapy have long been used for the effective treatment and prophylaxis of CNS, body malignancies, and leukaemias. However, they are not without their problems. Following the proliferation of magnetic resonance neuroimaging in recent years it has become clear that the spectrum of toxicity that these therapies produce ranges from subclinical white matter changes to overt brain necrosis. The effects are both direct and indirect and via different pathological mechanisms. Chronic and progressive changes can be detected many years after the initial intervention. In addition to leucoencephalopathic changes, grey matter changes are now well described. Changes may be difficult to distinguish from tumour recurrence, though may be reversible and remediable, and are thus very important to differentiate. In this review toxic effects are classified and their imaging appearances discussed, with reference to specific syndromes.

  5. VIIP: Central Nervous System (CNS) Modeling

    Science.gov (United States)

    Vera, Jerry; Mulugeta, Lealem; Nelson, Emily; Raykin, Julia; Feola, Andrew; Gleason, Rudy; Samuels, Brian; Ethier, C. Ross; Myers, Jerry

    2015-01-01

    Current long-duration missions to the International Space Station and future exploration-class missions beyond low-Earth orbit expose astronauts to increased risk of Visual Impairment and Intracranial Pressure (VIIP) syndrome. It has been hypothesized that the headward shift of cerebrospinal fluid (CSF) and blood in microgravity may cause significant elevation of intracranial pressure (ICP), which in turn may then induce VIIP syndrome through interaction with various biomechanical pathways. However, there is insufficient evidence to confirm this hypothesis. In this light, we are developing lumped-parameter models of fluid transport in the central nervous system (CNS) as a means to simulate the influence of microgravity on ICP. The CNS models will also be used in concert with the lumped parameter and finite element models of the eye described in the related IWS works submitted by Nelson et al., Feola et al. and Ethier et al.

  6. Experimental Study of Stellar Reactions at CNS

    International Nuclear Information System (INIS)

    After a brief review on low-energy RI beam production technology, nuclear astrophysics programs at CNS are presented including a scope of the field in the Wako campus. The CRIB project involves a total development of the whole facility to maximize the low-energy RI beam intensities, including the ion source, the AVF cyclotron and the low-energy RI beam separator CRIB, Some recent nuclear astrophysics experiments performed with the RI beams were discussed, including the measurement of the 14O(α,p)17F reaction, the key stellar reaction for the onset of the high-temperature rp-process. The first experiment performed with a newly installed high-resolution magnetic spectrograph PA of CNS was also presented. Collaboration possibilities for nuclear astrophysics in the RIKEN campus are also touched

  7. Notch1-Dll4 signalling and mechanical force regulate leader cell formation during collective cell migration.

    Science.gov (United States)

    Riahi, Reza; Sun, Jian; Wang, Shue; Long, Min; Zhang, Donna D; Wong, Pak Kin

    2015-03-13

    At the onset of collective cell migration, a subset of cells within an initially homogenous population acquires a distinct 'leader' phenotype with characteristic morphology and motility. However, the factors driving the leader cell formation as well as the mechanisms regulating leader cell density during the migration process remain to be determined. Here we use single-cell gene expression analysis and computational modelling to show that the leader cell identity is dynamically regulated by Dll4 signalling through both Notch1 and cellular stress in a migrating epithelium. Time-lapse microscopy reveals that Dll4 is induced in leader cells after the creation of the cell-free region and leader cells are regulated via Notch1-Dll4 lateral inhibition. Furthermore, mechanical stress inhibits Dll4 expression and leader cell formation in the monolayer. Collectively, our findings suggest that a reduction of mechanical force near the boundary promotes Notch1-Dll4 signalling to dynamically regulate the density of leader cells during collective cell migration.

  8. Regulation of Parvalbumin Basket cell plasticity in rule learning.

    Science.gov (United States)

    Caroni, Pico

    2015-04-24

    Local inhibitory Parvalbumin (PV)-expressing Basket cell networks shift to one of two possible opposite configurations depending on whether behavioral learning involves acquisition of new information or consolidation of validated rules. This reflects the existence of PV Basket cell subpopulations with distinct schedules of neurogenesis, output target neurons and roles in learning. Plasticity of hippocampal early-born PV neurons is recruited in rule consolidation, whereas plasticity of late-born PV neurons is recruited in new information acquisition. This involves regulation of early-born PV neuron plasticity specifically through excitation, and of late-born PV neuron plasticity specifically through inhibition. Therefore, opposite learning requirements are implemented by distinct local networks involving PV Basket cell subpopulations specifically regulated through inhibition or excitation.

  9. Ion channels involved in cell volume regulation: effects on migration, proliferation, and programmed cell death in non adherent EAT cells and adherent ELA cells.

    Science.gov (United States)

    Hoffmann, Else Kay

    2011-01-01

    This mini review outlines studies of cell volume regulation in two closely related mammalian cell lines: nonadherent Ehrlich ascites tumour cells (EATC) and adherent Ehrlich Lettre ascites (ELA) cells. Focus is on the regulatory volume decrease (RVD) that occurs after cell swelling, the volume regulatory ion channels involved, and the mechanisms (cellular signalling pathways) that regulate these channels. Finally, I shall also briefly review current investigations in these two cell lines that focuses on how changes in cell volume can regulate cell functions such as cell migration, proliferation, and programmed cell death.

  10. Sialylation regulates peripheral tolerance in CD4+ T cells.

    Science.gov (United States)

    Brennan, Patrick J; Saouaf, Sandra J; Van Dyken, Steve; Marth, Jamey D; Li, Bin; Bhandoola, Avinash; Greene, Mark I

    2006-05-01

    Decreased binding by the 6C10 auto-antibody serves as a unique marker for CD4+ T cell unresponsiveness after the induction of T cell tolerance in Vbeta8.1 TCR transgenic mice. We further define the nature of the epitope recognized by the 6C10 antibody to be a subset of Thy-1 bearing incompletely sialylated N-linked glycans, and furthermore, we demonstrate that tolerant CD4+ T cells have an increased degree of cell-surface sialylation. To test the significance of the altered glycosylation state identified by the 6C10 auto-antibody in the tolerant CD4+ T cell population, surface sialic acid was cleaved enzymatically. Treatment of purified peripheral CD4+ T cells with Vibrio cholerae sialidase (VCS) leads to increased 6C10 binding, significantly enhances proliferation in the tolerant CD4+ population and corrects defects in phosphotyrosine signaling observed in the tolerant CD4+ T cell. Furthermore, in vivo administration of VCS enhances proliferation in both tolerant and naive CD4+ T cell subsets. These studies suggest that sialylation of glycoproteins on the surface of the CD4+ T cell contributes to the regulation of T cell responsiveness in the tolerant state. PMID:16291658

  11. Studies on regulation of the cell cycle in fission yeast.

    Directory of Open Access Journals (Sweden)

    Miroslava Požgajová

    2015-05-01

    Full Text Available All living organisms including plants and animals are composed of millions of cells. These cells perform different functions for the organism although they possess the same chromosomes and carry the same genetic information. Thus, to be able to understand multicellular organism we need to understand the life cycle of individual cells from which the organism comprises. The cell cycle is the life cycle of a single cell in the plant or animal body. It involves series of events in which components of the cell doubles and afterwards equally segregate into daughter cells. Such process ensures growth of the organism, and specialized reductional cell division which leads to production of gamets, assures sexual reproduction. Cell cycle is divided in the G1, S, G2 and M phase. Two gap-phases (G1 and G2 separate S phase (or synthesis and M phase which stays either for mitosis or meiosis. Essential for normal life progression and reproduction is correct chromosome segregation during mitosis and meiosis. Defects in the division program lead to aneuploidy, which in turn leads to birth defects, miscarriages or cancer. Even thou, researchers invented much about the regulation of the cell cycle, there is still long way to understand the complexity of the regulatory machineries that ensure proper segregation of chromosomes. In this paper we would like to describe techniques and materials we use for our studies on chromosome segregation in the model organism Schizosaccharomyces pombe.

  12. Delivery of Therapeutic siRNA to the CNS Using Cationic and Anionic Liposomes.

    Science.gov (United States)

    Bender, Heather R; Kane, Sarah; Zabel, Mark D

    2016-07-23

    Prion diseases result from the misfolding of the normal, cellular prion protein (PrP(C)) to an abnormal protease resistant isomer called PrP(Res). The emergence of prion diseases in wildlife populations and their increasing threat to human health has led to increased efforts to find a treatment for these diseases. Recent studies have found numerous anti-prion compounds that can either inhibit the infectious PrP(Res) isomer or down regulate the normal cellular prion protein. However, most of these compounds do not cross the blood brain barrier to effectively inhibit PrP(Res) formation in brain tissue, do not specifically target neuronal PrP(C), and are often too toxic to use in animal or human subjects. We investigated whether siRNA delivered intravascularly and targeted towards neuronal PrP(C) is a safer and more effective anti-prion compound. This report outlines a protocol to produce two siRNA liposomal delivery vehicles, and to package and deliver PrP siRNA to neuronal cells. The two liposomal delivery vehicles are 1) complexed-siRNA liposome formulation using cationic liposomes (LSPCs), and 2) encapsulated-siRNA liposome formulation using cationic or anionic liposomes (PALETS). For the LSPCs, negatively charged siRNA is electrostatically bound to the cationic liposome. A positively charged peptide (RVG-9r [rabies virus glycoprotein]) is added to the complex, which specifically targets the liposome-siRNA-peptide complexes (LSPCs) across the blood brain barrier (BBB) to acetylcholine expressing neurons in the central nervous system (CNS). For the PALETS (peptide addressed liposome encapsulated therapeutic siRNA), the cationic and anionic lipids were rehydrated by the PrP siRNA. This procedure results in encapsulation of the siRNA within the cationic or anionic liposomes. Again, the RVG-9r neuropeptide was bound to the liposomes to target the siRNA/liposome complexes to the CNS. Using these formulations, we have successfully delivered PrP siRNA to Ach

  13. Latent progenitor cells as potential regulators for tympanic membrane regeneration

    Science.gov (United States)

    Kim, Seung Won; Kim, Jangho; Seonwoo, Hoon; Jang, Kyung-Jin; Kim, Yeon Ju; Lim, Hye Jin; Lim, Ki-Taek; Tian, Chunjie; Chung, Jong Hoon; Choung, Yun-Hoon

    2015-06-01

    Tympanic membrane (TM) perforation, in particular chronic otitis media, is one of the most common clinical problems in the world and can present with sensorineural healing loss. Here, we explored an approach for TM regeneration where the latent progenitor or stem cells within TM epithelial layers may play an important regulatory role. We showed that potential TM stem cells present highly positive staining for epithelial stem cell markers in all areas of normal TM tissue. Additionally, they are present at high levels in perforated TMs, especially in proximity to the holes, regardless of acute or chronic status, suggesting that TM stem cells may be a potential factor for TM regeneration. Our study suggests that latent TM stem cells could be potential regulators of regeneration, which provides a new insight into this clinically important process and a potential target for new therapies for chronic otitis media and other eardrum injuries.

  14. SOCS1 and Regulation of Regulatory T Cells Plasticity

    Directory of Open Access Journals (Sweden)

    Reiko Takahashi

    2014-01-01

    Full Text Available Several reports have suggested that natural regulatory T cells (Tregs lose Forkhead box P3 (Foxp3 expression and suppression activity under certain inflammatory conditions. Treg plasticity has been studied because it may be associated with the pathogenesis of autoimmunity. Some studies showed that a minor uncommitted Foxp3+ T cell population, which lacks hypomethylation at Treg-specific demethylation regions (TSDRs, may convert to effector/helper T cells. Suppressor of cytokine signaling 1 (SOCS1, a negative regulator of cytokine signaling, has been reported to play an important role in Treg cell integrity and function by protecting the cells from excessive inflammatory cytokines. In this review, we discuss Treg plasticity and maintenance of suppression functions in both physiological and pathological settings. In addition, we discuss molecular mechanisms of maintaining Treg plasticity by SOCS1 and other molecules. Such information will be useful for therapy of autoimmune diseases and reinforcement of antitumor immunity.

  15. Catalase regulates cell growth in HL60 human promyelocytic cells: evidence for growth regulation by H(2)O(2).

    Science.gov (United States)

    Hachiya, Misao; Akashi, Makoto

    2005-03-01

    Reactive oxygen species (ROS) including hydrogen peroxide (H(2)O(2)) are generated constitutively in mammalian cells. Because of its relatively long life and high permeability across membranes, H(2)O(2) is thought to be an important second messenger. Generation of H(2)O(2) is increased in response to external insults, including radiation. Catalase is located at the peroxisome and scavenges H(2)O(2). In this study, we investigated the role of catalase in cell growth using the H(2)O(2)-resistant variant HP100-1 of human promyelocytic HL60 cells. HP100-1 cells had an almost 10-fold higher activity of catalase than HL60 cells without differences in levels of glutathione peroxidase, manganese superoxide dismutase (MnSOD), and copper-zinc SOD (CuZnSOD). HP100-1 cells had higher proliferative activity than HL60 cells. Treatment with catalase or the introduction of catalase cDNA into HL60 cells stimulated cell growth. Exposure of HP100-1 cells to a catalase inhibitor resulted in suppression of cell growth with concomitant increased levels of intracellular H(2)O(2). Moreover, exogenously added H(2)O(2) or depletion of glutathione suppressed cell growth in HL60 cells. Extracellular signal regulated kinase 1/2 (ERK1/2) was constitutively phosphorylated in HP100-1 cells but not in HL60 cells. Inhibition of the ERK1/2 pathway suppressed the growth of HP100-1 cells, but inhibition of p38 mitogen-activated protein kinase (p38MAPK) did not affect growth. Moreover, inhibition of catalase blocked the phosphorylation of ERK1/2 but not of p38MAPK in HP100-1 cells. Thus our results suggest that catalase activates the growth of HL60 cells through dismutation of H(2)O(2), leading to activation of the ERK1/2 pathway; H(2)O(2) is an important regulator of growth in HL60 cells.

  16. Retinoic acid promotes the development of Arg1-expressing dendritic cells for the regulation of T-cell differentiation

    OpenAIRE

    Chang, Jinsam; Thangamani, Shankar; Kim, Myung H.; Ulrich, Benjamin; Morris, Sidney M.; Chang H Kim

    2013-01-01

    Arginase I (Arg1), an enzyme expressed by many cell types including myeloid cells, can regulate immune responses. Expression of Arg1 in myeloid cells is regulated by a number of cytokines and tissue factors that influence cell development and activation. Retinoic acid, produced from vitamin A, regulates the homing and differentiation of lymphocytes and plays important roles in the regulation of immunity and immune tolerance. We report here that optimal expression of Arg1 in dendritic cells re...

  17. Cell fate regulation governed by a repurposed bacterial histidine kinase.

    Directory of Open Access Journals (Sweden)

    W Seth Childers

    2014-10-01

    Full Text Available One of the simplest organisms to divide asymmetrically is the bacterium Caulobacter crescentus. The DivL pseudo-histidine kinase, positioned at one cell pole, regulates cell-fate by controlling the activation of the global transcription factor CtrA via an interaction with the response regulator (RR DivK. DivL uniquely contains a tyrosine at the histidine phosphorylation site, and can achieve these regulatory functions in vivo without kinase activity. Determination of the DivL crystal structure and biochemical analysis of wild-type and site-specific DivL mutants revealed that the DivL PAS domains regulate binding specificity for DivK∼P over DivK, which is modulated by an allosteric intramolecular interaction between adjacent domains. We discovered that DivL's catalytic domains have been repurposed as a phosphospecific RR input sensor, thereby reversing the flow of information observed in conventional histidine kinase (HK-RR systems and coupling a complex network of signaling proteins for cell-fate regulation.

  18. Current and Future Stem Cell Regulation: A Call to Action.

    Science.gov (United States)

    Anz, Adam

    2016-01-01

    The orthopedic sports medicine profession experienced a pivotal shift with the acceptance and application of the arthroscope. The next leap forward will hinge on the acceptance, application, and regulation of biologic therapies, and a sentinel event will be the US Food and Drug Administration approval of a stem cell technology. While the arthroscope was developed in the hands of our sports medicine mentors, the current history of biologics has been mostly written by basic scientists. The baby steps of these technologies have involved benchtop laboratory studies and preclinical animal trials, clearly illustrating great potential. Clinical progress has struggled forward but stalled. Regulatory constraints and our inability to establish safety and efficacy are the major hurdles, with disconnect between the basic scientist, clinician, and regulatory bodies to blame. While the development of the arthroscope was barely influenced by governmental regulation, this will control and model the future of stem cell technologies. With current legislation before Congress concerning stem cell regulation, the next steps are dependent upon the clinician's understanding and participation in this regulation. PMID:27552450

  19. Fulminant lymphocytic choriomeningitis virus-induced inflammation of the CNS involves a cytokine-chemokine-cytokine-chemokine cascade

    DEFF Research Database (Denmark)

    Christensen, Jeanette E; Simonsen, Stine; Fenger, Christina;

    2009-01-01

    Intracerebral inoculation of immunocompetent mice with lymphocytic choriomeningitis virus (LCMV) normally results in fatal CD8+ T cell mediated meningoencephalitis. However, in CXCL10-deficient mice, the virus-induced CD8+ T cell accumulation in the neural parenchyma is impaired, and only 30...... of the CNS, and astrocytes are the dominant expressors in the neural parenchyma, not microglial cells or recruited bone marrow-derived cell types. These results are consistent with a model suggesting a bidirectional interplay between resident cells of the CNS and the recruited virus-specific T cells...

  20. Salvianolic acid B ameliorates CNS autoimmunity by suppressing Th1 responses.

    Science.gov (United States)

    Dong, Zhihui; Ma, Dihui; Gong, Ye; Yu, Tingmin; Yao, Gang

    2016-04-21

    Experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS), is a Th1 and Th17 cell-mediated CNS autoimmune disease. Therefore, immune regulation is a key target for therapy. Salvianolic acid B (Sal B) is a major water-soluble bioactive component of the famous traditional Chinese medicine Salvia miltiorrhiza, which is notable for its anti-oxidative and anti-inflammatory effects. Thus Sal B, by impairing Th1 or Th17 responses in EAE/MS, might ameliorate the crippling symptoms. Here we show that the intraperitoneal administration of 30mg/kg Sal B daily for 14 days after the onset of MOG-induced EAE in mice effectively reduced its severity. Additionally, Sal B treatment downgraded the infiltration of inflammatory cells, limited astrogliosis and blocked Th1 responses other than that of Th17. These results indicated that Sal B may serve as an effective therapeutic agent for MS/EAE by inhibiting Th1 cell responses. PMID:26777627

  1. FOXP3 ensembles in T-cell regulation.

    Science.gov (United States)

    Li, Bin; Samanta, Arabinda; Song, Xiaomin; Furuuchi, Keiji; Iacono, Kathryn T; Kennedy, Sarah; Katsumata, Makoto; Saouaf, Sandra J; Greene, Mark I

    2006-08-01

    Our recent studies have identified dynamic protein ensembles containing forkhead box protein 3 (FOXP3) that provide insight into the molecular complexity of suppressor T-cell activities, and it is our goal to determine how these ensembles regulate FOXP3's transcriptional activity in vivo. In this review, we summarize our current understanding of how FOXP3 expression is induced and how FOXP3 functions in vivo as a transcriptional regulator by assembling a multisubunit complex involved in histone modification as well as chromatin remodeling. PMID:16903909

  2. Regulation of apoptosis and cell cycle in irradiated mouse brain

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Won Yong; Song, Mi Hee; Hung, Eun Ji; Seong, Jin Sil; Suh, Chang Ok [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2001-06-01

    To investigate the regulation of apoptosis and cell cycle in mouse brain irradiation. 8-week old male mice, C57B 1/6J were given whole body {gamma} -radiation with a single dose of 25 Gy using Cobalt 60 irradiator. At different times 1, 2, 4, 8 and 24hr after irradiation, mice were killed and brain tissues were collected. Apoptotic cells were scored by TUNEL assay. Expression of p53, Bcl-2, and Bax and cell cycle regulating molecules; cyclins BI, D1, E and cdk2, cdk4, p34{sup cdc2} were analysed by Western blotting. Cell cycle was analysed by flow cytometry. The peak of radiation induced apoptosis is shown at 8 hour after radiation. With a single 25 Gy irradiation, the peak of apoptotic index in C57B1/6J is 24.0{+-}0.25 (p<0.05) at 8 hour after radiation. Radiation upregulated the expression of p53/tubulin, Bax/tubulin, and Bcl-2/tubulin with 1.3, 1.1 and 1.45 fold increase, respectively were shown at the peak level at 8 hour after radiation. The levels of cell cycle regulating molecules after radiation are not changed significantly except cyclin D1 with 1.3 fold increase. Fractions of Go-G 1, G2-M and S phase in the cell cycle does not specific changes by time. In mouse brain tissue, radiation induced apoptosis is particularly shown in a specific area, subependyma. These results and lack of radiation induced changes in cell cycle offer better understanding of radiation response of normal brain tissue.

  3. The regulation of CD5 expression in murine T cells

    Directory of Open Access Journals (Sweden)

    Herzenberg Leonard A

    2001-05-01

    Full Text Available Abstract Background CD5 is a pan-T cell surface marker that is also present on a subset of B cells, B-1a cells.Functional and developmental subsets of T cells express characteristic CD5 levels that vary over roughly a 30-fold range. Previous investigators have cloned a 1.7 Kb fragment containing the CD5 promoter and showed that it can confer similar lymphocyte-specific expression pattern as observed for endogenous CD5 expression. Results We further characterize the CD5 promoter and identify minimal and regulatory regions on the CD5 promoter. Using a luciferase reporter system, we show that a 43 bp region on the CD5 promoter regulates CD5 expression in resting mouse thymoma EL4 T cells and that an Ets binding site within the 43 bp region mediates the CD5 expression. In addition, we show that Ets-1, a member of the Ets family of transcription factors, recognizes the Ets binding site in the electrophoretic mobility shift assay (EMSA. This Ets binding site is directly responsible for the increase in reporter activity when co-transfected with increasing amounts of Ets-1 expression plasmid. We also identify two additional evolutionarily-conserved regions in the CD5 promoter (CD5X and CD5Y and demonstrate the respective roles of the each region in the regulation of CD5 transcription. Conclusion Our studies define a minimal and regulatory promoter for CD5 and show that the CD5 expression level in T cells is at least partially dependent on the level of Ets-1 protein. Based on the findings in this report, we propose a model of CD5 transcriptional regulation in T cells.

  4. SENP1 regulates cell migration and invasion in neuroblastoma.

    Science.gov (United States)

    Xiang-Ming, Yan; Zhi-Qiang, Xu; Ting, Zhang; Jian, Wang; Jian, Pan; Li-Qun, Yuan; Ming-Cui, Fu; Hong-Liang, Xia; Xu, Cao; Yun, Zhou

    2016-05-01

    Neuroblastoma (NB) is an embryonic solid tumor derived from precursor cells of the sympathetic nervous system, and accounts for 11% of childhood cancers and around 15% of cancer deaths in children. SUMOylation and deSUMOylation are dynamic mechanisms regulating a spectrum of protein activities. The SUMO proteases (SENP) remove SUMO conjugate from proteins, and their expression is deregulated in diverse cancers. However, nothing is known about the role of SENPs in NBL. In the present study, we found that SENP1 expression was significantly high in metastatic NB tissues compared with primary NB tissues. Overexpression of SENP1 promoted NB cells migration and invasion. Inhibition of SENP1 could significantly suppress NB cell migration and invasion. Moreover, we found that SENP1 could regulate the expression of CDH1, MMP9, and MMP2. In summary, the data presented here indicate a significant role of SENP1 in the regulation of cell migration and invasion in NB and suppress SENP1 expression as promising candidates for novel treatment strategies of NB.

  5. SINS/CNS Nonlinear Integrated Navigation Algorithm for Hypersonic Vehicle

    Directory of Open Access Journals (Sweden)

    Yong-jun Yu

    2015-01-01

    Full Text Available Celestial Navigation System (CNS has characteristics of accurate orientation and strong autonomy and has been widely used in Hypersonic Vehicle. Since the CNS location and orientation mainly depend upon the inertial reference that contains errors caused by gyro drifts and other error factors, traditional Strap-down Inertial Navigation System (SINS/CNS positioning algorithm setting the position error between SINS and CNS as measurement is not effective. The model of altitude azimuth, platform error angles, and horizontal position is designed, and the SINS/CNS tightly integrated algorithm is designed, in which CNS altitude azimuth is set as measurement information. GPF (Gaussian particle filter is introduced to solve the problem of nonlinear filtering. The results of simulation show that the precision of SINS/CNS algorithm which reaches 130 m using three stars is improved effectively.

  6. The cell cycle-regulated genes of Schizosaccharomyces pombe.

    Directory of Open Access Journals (Sweden)

    Anna Oliva

    2005-07-01

    Full Text Available Many genes are regulated as an innate part of the eukaryotic cell cycle, and a complex transcriptional network helps enable the cyclic behavior of dividing cells. This transcriptional network has been studied in Saccharomyces cerevisiae (budding yeast and elsewhere. To provide more perspective on these regulatory mechanisms, we have used microarrays to measure gene expression through the cell cycle of Schizosaccharomyces pombe (fission yeast. The 750 genes with the most significant oscillations were identified and analyzed. There were two broad waves of cell cycle transcription, one in early/mid G2 phase, and the other near the G2/M transition. The early/mid G2 wave included many genes involved in ribosome biogenesis, possibly explaining the cell cycle oscillation in protein synthesis in S. pombe. The G2/M wave included at least three distinctly regulated clusters of genes: one large cluster including mitosis, mitotic exit, and cell separation functions, one small cluster dedicated to DNA replication, and another small cluster dedicated to cytokinesis and division. S. pombe cell cycle genes have relatively long, complex promoters containing groups of multiple DNA sequence motifs, often of two, three, or more different kinds. Many of the genes, transcription factors, and regulatory mechanisms are conserved between S. pombe and S. cerevisiae. Finally, we found preliminary evidence for a nearly genome-wide oscillation in gene expression: 2,000 or more genes undergo slight oscillations in expression as a function of the cell cycle, although whether this is adaptive, or incidental to other events in the cell, such as chromatin condensation, we do not know.

  7. Role of Hemichannels in CNS Inflammation and the Inflammasome Pathway.

    Science.gov (United States)

    Kim, Yuri; Davidson, Joanne O; Gunn, Katherine C; Phillips, Anthony R; Green, Colin R; Gunn, Alistair J

    2016-01-01

    Neurodegenerative, cardiovascular, and metabolic disorders, once triggered, share a number of common features, including sustained inflammatory cell activation and vascular disruption. These shared pathways are induced independently of any genetic predisposition to the disease or the precise external stimulus. Glial cells respond to injury with an innate immune response that includes release of proinflammatory cytokines and chemokines. Vascular endothelial cells may also be affected, leading to opening of the blood-brain barrier that facilitates invasion by circulating inflammatory cells. Inflammation can trigger acute neural injury followed by chronic inflammation that plays a key role in neurodegenerative conditions. Gap junction channels normally allow direct cell-to-cell communication. They are formed by the docking of two hemichannels, one contributed by each of the neighboring cells. While the opening probability of these channels is tightly controlled under resting conditions, hemichannels can open in response to injury or inflammatory factors, forming a large, relatively nonselective membrane pore. In this review, we consider the CNS immune system from the perspective that modulating connexin hemichannel opening can prevent tissue damage arising from excessive and uncontrolled inflammation. We discuss connexin channel roles in microglia, astrocytes, and endothelial cells in both acute and chronic inflammatory conditions, and in particular describe the role of connexin hemichannels in the inflammasome pathway where they contribute to both its activation and its spread to neighboring cells. Finally, we describe the benefits of hemichannel block in animal models of brain injury. PMID:27038371

  8. Lipoxin A4 regulates natural killer cell and type 2 innate lymphoid cell activation in asthma

    OpenAIRE

    Barnig, C.; Cernadas, M; Dutile, S.; Liu, X.; Perrella, M A; Kazani, S.; Wechsler, M.E.; Israel, E; Levy, B.D.

    2013-01-01

    Asthma is a prevalent disease of chronic inflammation in which endogenous counter-regulatory signaling pathways are dysregulated. Recent evidence suggests that innate lymphoid cells (ILCs), including natural killer (NK) cells and type 2 innate lymphoid cells (ILC2), can participate in the regulation of allergic airways responses, in particular airway mucosal inflammation. Here, we have identified both NK cells and ILC2 in human lung and peripheral blood in healthy and asthmatic subjects. NK c...

  9. Thymus-dependent sensitizing processes involved in the induction of CNS disease in mice by parainfluenza type 1 virus

    International Nuclear Information System (INIS)

    Parainfluenza type 1 virus injected intracerebrally into adult mice induced a mononuclear cell infiltration in the subarchnoidal and perivascular spaces, exudation of inflammatory cells into parenchymal tissue and preferential chronic degeneration of white matter. No correlation was found between the severity of the central nervous system (CNS)2 lesions and the levels of circulating hemagglutination inhibition antibody. Inactivation of the virus by ultraviolet light (uv) did not affect the ability of the virus to produce the CNS lesions in these mice. As part of an inquiry into the mechanisms involved in the production of CNS lesions, the present study reports the response of athymic nude mice and sensitization through prior CNS exposure to virus antigen in immunocompetent mice. (U.S.)

  10. Hedgehog signaling regulates telomerase reverse transcriptase in human cancer cells.

    Directory of Open Access Journals (Sweden)

    Tapati Mazumdar

    Full Text Available The Hedgehog (HH signaling pathway is critical for normal embryonic development, tissue patterning and cell differentiation. Aberrant HH signaling is involved in multiple human cancers. HH signaling involves a multi-protein cascade activating the GLI proteins that transcriptionally regulate HH target genes. We have previously reported that HH signaling is essential for human colon cancer cell survival and inhibition of this signal induces DNA damage and extensive cell death. Here we report that the HH/GLI axis regulates human telomerase reverse transcriptase (hTERT, which determines the replication potential of cancer cells. Suppression of GLI1/GLI2 functions by a C-terminus truncated GLI3 repressor mutant (GLI3R, or by GANT61, a pharmacological inhibitor of GLI1/GLI2, reduced hTERT protein expression in human colon cancer, prostate cancer and Glioblastoma multiforme (GBM cell lines. Expression of an N-terminus deleted constitutively active mutant of GLI2 (GLI2ΔN increased hTERT mRNA and protein expression and hTERT promoter driven luciferase activity in human colon cancer cells while GANT61 inhibited hTERT mRNA expression and hTERT promoter driven luciferase activity. Chromatin immunoprecipitation with GLI1 or GLI2 antibodies precipitated fragments of the hTERT promoter in human colon cancer cells, which was reduced upon exposure to GANT61. In contrast, expression of GLI1 or GLI2ΔN in non-malignant 293T cells failed to alter the levels of hTERT mRNA and protein, or hTERT promoter driven luciferase activity. Further, expression of GLI2ΔN increased the telomerase enzyme activity, which was reduced by GANT61 administration in human colon cancer, prostate cancer, and GBM cells. These results identify hTERT as a direct target of the HH signaling pathway, and reveal a previously unknown role of the HH/GLI axis in regulating the replication potential of cancer cells. These findings are of significance in understanding the important regulatory

  11. Regulation of osteoprotegerin expression by Notch signaling in human oral squamous cell carcinoma cell line

    Institute of Scientific and Technical Information of China (English)

    Jeeranan Manokawinchoke; Thanaphum Osathanon; Prasit Pavasant

    2016-01-01

    Objective: To investigate the influence of Notch signaling on osteoprotegerin (OPG) expression in a human oral squamous cell carcinoma cell line. Methods: Activation of Notch signaling was performed by seeding cells on Jagged1 immobilized surfaces. In other experiments, a γ-secretase inhibitor was added to the culture medium to inhibit intracellular Notch signaling. OPG mRNA and protein were determined by real-time PCR and ELISA, respectively. Finally, publicly available microarray database analysis was performed using connection up- or down-regulation expression analysis of microarrays software. Results: Jagged1-treatment of HSC-4 cells enhanced HES1 and HEY1 mRNA expres-sion, confirming the intracellular activation of Notch signaling. OPG mRNA and protein levels were significantly suppressed upon Jagged1 treatment. Correspondingly, HSC-4 cells treated with a γ-secretase inhibitor resulted in a significant reduction of HES1 and HEY1 mRNA levels, and a marked increase in OPG protein expression was observed. These results implied that Notch signaling regulated OPG expression in HSC-4 cells. However, Jagged1 did not alter OPG expression in another human oral squamous cell carcinoma cell line (HSC-5) or a human head and neck squamous cell carcinoma cell line (HN22). Conclusions: Notch signaling regulated OPG expression in an HSC-4 cell line and this mechanism could be cell line specific.

  12. Leading research on cell proliferation regulation technology; Saibo zoshoku seigyo gijutsu no sendo kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For developing intelligent material, animal test alternative model, bio-cell analysis equipment, self-controlling bio-reactor and medical material, development of functional cells was studied by cell proliferation regulation technology. In fiscal 1996, the expression analysis and separation technology of specific gene for cell proliferation, and the intracellular regulation technology were surveyed from the viewpoint of intracellular regulation. The cell proliferation regulation technology by specific regulating material of cells, extracellular matrix, coculture system and embryonic cell was surveyed from the viewpoint of extracellular regulation. In addition, based on these survey results, new cell culture/analysis technology, new bio-material, artificial organ system, energy saving bio-reactor, environment purification microorganism, and animal test alternative model were surveyed as applications to industrial basic technologies from a long-term viewpoint. The approach to cell proliferation regulation requires preparation of a concrete proliferation regulation technology system of cells, and concrete application targets. 268 refs., 43 figs., 4 tabs.

  13. MicroRNAs as biomarkers for CNS disease

    Directory of Open Access Journals (Sweden)

    Pooja eRao

    2013-11-01

    Full Text Available For many neurological diseases, the efficacy and outcome of treatment depend on early detection. Diagnosis is currently based on the detection of symptoms and neuroimaging abnormalities, which appear at relatively late stages in the pathogenesis. However, the underlying molecular responses to genetic and environmental insults begin much earlier and non-coding RNA networks are critically involved in these cellular regulatory mechanisms. Profiling RNA expression patterns could thus facilitate presymptomatic disease detection.Obtaining indirect readouts of pathological processes is particularly important for brain disorders because of the lack of direct access to tissue for molecular analyses. Living neurons and other CNS cells secrete microRNA and other small non-coding RNA into the extracellular space packaged in exosomes, microvesicles or lipoprotein complexes. This discovery, together with the rapidly evolving massive sequencing technologies that allow detection of virtually all RNA species from small amounts of biological material, has allowed significant progress in the use of extracellular RNA as a biomarker for CNS malignancies, neurological and psychiatric diseases. There is also recent evidence that the interactions between external stimuli and brain pathological processes may be reflected in peripheral tissues, facilitating their use as potential diagnostic markers. In this review, we explore the possibilities and challenges of using microRNA and other small RNAs as a signature for neurodegenerative and other neuropsychatric conditions.

  14. Protein kinase D regulates cell death pathways in experimental pancreatitis

    Directory of Open Access Journals (Sweden)

    Jingzhen eYuan

    2012-03-01

    Full Text Available Inflammation and acinar cell necrosis are two major pathological responses of acute pancreatitis, a serious disorder with no current therapies directed to its molecular pathogenesis. Serine/threonine protein kinase D family, which includes PKD/PKD1, PKD2, and PKD3, has been increasingly implicated in the regulation of multiple physiological and pathophysiological effects. We recently reported that PKD/PKD1, the predominant PKD isoform expressed in rat pancreatic acinar cells, mediates early events of pancreatitis including NF-kappaB activation and inappropriate intracellular digestive enzyme activation. In current studies, we investigated the role and mechanisms of PKD/PKD1 in the regulation of necrosis in pancreatic acinar cells by using two novel small molecule PKD inhibitors CID755673 and CRT0066101 and molecular approaches in in vitro and in vivo experimental models of acute pancreatitis. Our results demonstrated that both CID755673 and CRT0066101 are PKD-specific inhibitors and that PKD/PKD1 inhibition by either the chemical inhibitors or specific PKD/PKD1 siRNAs attenuated necrosis while promoting apoptosis induced by pathological doses of cholecystokinin-octapeptide (CCK in pancreatic acinar cells. Conversely, upregulation of PKD expression in pancreatic acinar cells increased necrosis and decreased apoptosis. We further showed that PKD/PKD1 regulated several key cell death signals including inhibitors of apoptotic proteins (IAPs, caspases, receptor-interacting protein kinase 1 (RIP1 to promote necrosis. PKD/PKD1 inhibition by CID755673 significantly ameliorated necrosis and severity of pancreatitis in an in vivo experimental model of acute pancreatitis. Thus, our studies indicate that PKD/PKD1 is a key mediator of necrosis in acute pancreatitis and that PKD/PKD1 may represent a potential therapeutic target in acute pancreatitis.

  15. PPARδ regulates satellite cell proliferation and skeletal muscle regeneration

    Directory of Open Access Journals (Sweden)

    Angione Alison R

    2011-11-01

    Full Text Available Abstract Peroxisome proliferator-activated receptors (PPARs are a class of nuclear receptors that play important roles in development and energy metabolism. Whereas PPARδ has been shown to regulate mitochondrial biosynthesis and slow-muscle fiber types, its function in skeletal muscle progenitors (satellite cells is unknown. Since constitutive mutation of Pparδ leads to embryonic lethality, we sought to address this question by conditional knockout (cKO of Pparδ using Myf5-Cre/Pparδflox/flox alleles to ablate PPARδ in myogenic progenitor cells. Although Pparδ-cKO mice were born normally and initially displayed no difference in body weight, muscle size or muscle composition, they later developed metabolic syndrome, which manifested as increased body weight and reduced response to glucose challenge at age nine months. Pparδ-cKO mice had 40% fewer satellite cells than their wild-type littermates, and these satellite cells exhibited reduced growth kinetics and proliferation in vitro. Furthermore, regeneration of Pparδ-cKO muscles was impaired after cardiotoxin-induced injury. Gene expression analysis showed reduced expression of the Forkhead box class O transcription factor 1 (FoxO1 gene in Pparδ-cKO muscles under both quiescent and regenerating conditions, suggesting that PPARδ acts through FoxO1 in regulating muscle progenitor cells. These results support a function of PPARδ in regulating skeletal muscle metabolism and insulin sensitivity, and they establish a novel role of PPARδ in muscle progenitor cells and postnatal muscle regeneration.

  16. Splicing Regulation: A Molecular Device to Enhance Cancer Cell Adaptation

    Directory of Open Access Journals (Sweden)

    Vittoria Pagliarini

    2015-01-01

    Full Text Available Alternative splicing (AS represents a major resource for eukaryotic cells to expand the coding potential of their genomes and to finely regulate gene expression in response to both intra- and extracellular cues. Cancer cells exploit the flexible nature of the mechanisms controlling AS in order to increase the functional diversity of their proteome. By altering the balance of splice isoforms encoded by human genes or by promoting the expression of aberrant oncogenic splice variants, cancer cells enhance their ability to adapt to the adverse growth conditions of the tumoral microenvironment. Herein, we will review the most relevant cancer-related splicing events and the underlying regulatory mechanisms allowing tumour cells to rapidly adapt to the harsh conditions they may face during the occurrence and development of cancer.

  17. The rostral migratory stream plays a key role in intranasal delivery of drugs into the CNS.

    Directory of Open Access Journals (Sweden)

    Robert A Scranton

    Full Text Available BACKGROUND: The blood brain barrier (BBB is impermeable to most drugs, impeding the establishment of novel neuroprotective therapies and strategies for many neurological diseases. Intranasal administration offers an alternative path for efficient drug delivery into the CNS. So far, the anatomical structures discussed to be involved in the transport of intranasally administered drugs into the CNS include the trigeminal nerve, olfactory nerve and the rostral migratory stream (RMS, but the relative contributions are debated. METHODS AND FINDINGS: In the present study we demonstrate that surgical transection, and the resulting structural disruption of the RMS, in mice effectively obstructs the uptake of intranasally administered radioligands into the CNS. Furthermore, using a fluorescent cell tracer, we demonstrate that intranasal administration in mice allows agents to be distributed throughout the entire brain, including olfactory bulb, hippocampus, cortex and cerebellum. CONCLUSIONS: This study provides evidence of the vital role the RMS has in the CNS delivery of intranasally administered agents. The identification of the RMS as the major access path for intranasally administered drugs into the CNS may contribute to the development of treatments that are tailored for efficient transport within this structure. Research into the RMS needs to continue to elucidate its limitations, capabilities, mechanisms of transport and potential hazards before we are able to advance this technique into human research.

  18. The emerging role of in vitro electrophysiological methods in CNS safety pharmacology.

    Science.gov (United States)

    Accardi, Michael V; Pugsley, Michael K; Forster, Roy; Troncy, Eric; Huang, Hai; Authier, Simon

    2016-01-01

    Adverse CNS effects account for a sizeable proportion of all drug attrition cases. These adverse CNS effects are mediated predominately by off-target drug activity on neuronal ion-channels, receptors, transporters and enzymes - altering neuronal function and network communication. In response to these concerns, there is growing support within the pharmaceutical industry for the requirement to perform more comprehensive CNS safety testing prior to first-in-human trials. Accordingly, CNS safety pharmacology commonly integrates several in vitro assay methods for screening neuronal targets in order to properly assess therapeutic safety. One essential assay method is the in vitro electrophysiological technique - the 'gold standard' ion channel assay. The in vitro electrophysiological method is a useful technique, amenable to a variety of different tissues and cell configurations, capable of assessing minute changes in ion channel activity from the level of a single receptor to a complex neuronal network. Recent advances in automated technology have further expanded the usefulness of in vitro electrophysiological methods into the realm of high-throughput, addressing the bottleneck imposed by the manual conduct of the technique. However, despite a large range of applications, manual and automated in vitro electrophysiological techniques have had a slow penetrance into the field of safety pharmacology. Nevertheless, developments in throughput capabilities and in vivo applicability have led to a renewed interest in in vitro electrophysiological techniques that, when complimented by more traditional safety pharmacology methods, often increase the preclinical predictability of potential CNS liabilities.

  19. A mechanistic stochastic framework for regulating bacterial cell division.

    Science.gov (United States)

    Ghusinga, Khem Raj; Vargas-Garcia, Cesar A; Singh, Abhyudai

    2016-01-01

    How exponentially growing cells maintain size homeostasis is an important fundamental problem. Recent single-cell studies in prokaryotes have uncovered the adder principle, where cells add a fixed size (volume) from birth to division, irrespective of their size at birth. To mechanistically explain the adder principle, we consider a timekeeper protein that begins to get stochastically expressed after cell birth at a rate proportional to the volume. Cell-division time is formulated as the first-passage time for protein copy numbers to hit a fixed threshold. Consistent with data, the model predicts that the noise in division timing increases with size at birth. Intriguingly, our results show that the distribution of the volume added between successive cell-division events is independent of the newborn cell size. This was dramatically seen in experimental studies, where histograms of the added volume corresponding to different newborn sizes collapsed on top of each other. The model provides further insights consistent with experimental observations: the distribution of the added volume when scaled by its mean becomes invariant of the growth rate. In summary, our simple yet elegant model explains key experimental findings and suggests a mechanism for regulating both the mean and fluctuations in cell-division timing for controlling size. PMID:27456660

  20. Mitochondrial peroxiredoxin 3 regulates sensory cell survival in the cochlea.

    Directory of Open Access Journals (Sweden)

    Fu-Quan Chen

    Full Text Available This study delineates the role of peroxiredoxin 3 (Prx3 in hair cell death induced by several etiologies of acquired hearing loss (noise trauma, aminoglycoside treatment, age. In vivo, Prx3 transiently increased in mouse cochlear hair cells after traumatic noise exposure, kanamycin treatment, or with progressing age before any cell loss occurred; when Prx3 declined, hair cell loss began. Maintenance of high Prx3 levels via treatment with the radical scavenger 2,3-dihydroxybenzoate prevented kanamycin-induced hair cell death. Conversely, reducing Prx3 levels with Prx3 siRNA increased the severity of noise-induced trauma. In mouse organ of Corti explants, reactive oxygen species and levels of Prx3 mRNA and protein increased concomitantly at early times of drug challenge. When Prx3 levels declined after prolonged treatment, hair cells began to die. The radical scavenger p-phenylenediamine maintained Prx3 levels and attenuated gentamicin-induced hair cell death. Our results suggest that Prx3 is up-regulated in response to oxidative stress and that maintenance of Prx3 levels in hair cells is a critical factor in their susceptibility to acquired hearing loss.

  1. A mechanistic stochastic framework for regulating bacterial cell division.

    Science.gov (United States)

    Ghusinga, Khem Raj; Vargas-Garcia, Cesar A; Singh, Abhyudai

    2016-07-26

    How exponentially growing cells maintain size homeostasis is an important fundamental problem. Recent single-cell studies in prokaryotes have uncovered the adder principle, where cells add a fixed size (volume) from birth to division, irrespective of their size at birth. To mechanistically explain the adder principle, we consider a timekeeper protein that begins to get stochastically expressed after cell birth at a rate proportional to the volume. Cell-division time is formulated as the first-passage time for protein copy numbers to hit a fixed threshold. Consistent with data, the model predicts that the noise in division timing increases with size at birth. Intriguingly, our results show that the distribution of the volume added between successive cell-division events is independent of the newborn cell size. This was dramatically seen in experimental studies, where histograms of the added volume corresponding to different newborn sizes collapsed on top of each other. The model provides further insights consistent with experimental observations: the distribution of the added volume when scaled by its mean becomes invariant of the growth rate. In summary, our simple yet elegant model explains key experimental findings and suggests a mechanism for regulating both the mean and fluctuations in cell-division timing for controlling size.

  2. Role of Ran GTPase in cell cycle regulation

    Institute of Scientific and Technical Information of China (English)

    JIANG Qing; LU Zhigang; ZHANG Chuanmao

    2004-01-01

    Ran, a member of the Ras GTPase superfamily,is a multifunctional protein and abundant in the nucleus.Many evidences suggest that Ran and its interacting proteins are involved in multiple aspects of the cell cycle regulation.So far it has been conformed that Ran and its interacting proteins control the nucleocytoplasmic transport, the nuclear envelope (NE) assembly, the DNA replication and the spindle assembly, although many details of the mechanisms are waiting for elucidation. It has also been implicated that Ran and its interacting proteins are involved in regulating the integrity of the nuclear structure, the mRNA transcription and splicing, and the RNA transport from the nucleus to the cytoplasm. In this review we mainly discuss the mechanisms by which Ran and its interacting proteins regulate NE assembly, DNA replication and spindle assembly.

  3. Mathematical modeling of the cells repair regulations in Nasopharyngeal carcinoma.

    Science.gov (United States)

    Adi-Kusumo, Fajar; Wiraya, Ario

    2016-07-01

    Nasopharyngeal Carcinoma (NPC) is a malignant cancer which is caused by the activation of Epstein-Barr Virus (EBV) via some external factors. In the cells repair regulations, the p53 gene mutation can be used as the early indication of the NPC growth. The NPC growth is due to the DNA damage accumulation caused by the EBV infection. In this paper we construct the cells repair regulations model to characterize the NPC growth. The model is a 15 dimensional of first order ODE system and consists the proteins and enzymes reactions. We do some numerical simulations to show the inactivation of the phosphorylated and acetylated p53, and the chromosomal instability of p53 gene, which can be used as the earlier stage detection of NPC. PMID:27140528

  4. MicroRNA-21 regulates stemness in cancer cells

    OpenAIRE

    Kang, Hong-Yo

    2013-01-01

    MicroRNA-21 (miR-21) functions have been linked to cancer progression and chemo- or radiotherapy resistance. While an increasing number of studies have reported a potential role of miR-21 expression in promoting growth of a small population of stem/progenitor cells, knowledge on its role as a regulator of stemness in cancers remains limited. In a previous issue of Stem Cell Research &Therapy, Chung and colleagues provide evidence that miR-21 is highly expressed in stem/progenitor populations ...

  5. BRCA1-Dependent Translational Regulation in Breast Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Estelle Dacheux

    Full Text Available BRCA1 (Breast Cancer 1 has been implicated in a number of cellular processes, including transcription regulation, DNA damage repair and protein ubiquitination. We previously demonstrated that BRCA1 interacts with PABP1 (Poly(A-Binding Protein 1 and that BRCA1 modulates protein synthesis through this interaction. To identify the mRNAs that are translationally regulated by BRCA1, we used a microarray analysis of polysome-bound mRNAs in BRCA1-depleted and non-depleted MCF7 cells. Our findings show that BRCA1 modifies the translational efficiency of approximately 7% of the mRNAs expressed in these cells. Further analysis revealed that several processes contributing to cell surveillance such as cell cycle arrest, cell death, cellular growth and proliferation, DNA repair and gene expression, are largely enriched for the mRNAs whose translation is impacted by BRCA1. The BRCA1-dependent translation of these species of mRNAs therefore uncovers a novel mechanism through which BRCA1 exerts its onco-suppressive role. In addition, the BRCA1-dependent translation of mRNAs participating in unexpected functions such as cellular movement, nucleic acid metabolism or protein trafficking is indicative of novel functions for BRCA1. Finally, this study contributes to the identification of several markers associated with BRCA1 deficiency and to the discovery of new potential anti-neoplastic therapeutic targets.

  6. Cbl negatively regulates JNK activation and cell death

    Institute of Scientific and Technical Information of China (English)

    Andrew A Sproul; Zhiheng Xu; Michael Wilhelm; Stephen Gire; Lloyd A Greene

    2009-01-01

    Here, we explore the role of Cbl proteins in regulation of neuronal apoptosis. In two paradigms of neuron apopto-sis--nerve growth factor (NGF) deprivation and DNA damage--cellular levels of c-Cbl and Cbl-b fell well before the onset of cell death. NGF deprivation also induced rapid loss of tyrosine phosphorylation (and most likely, activa-tion) of c-Cbl. Targeting e-Cbl and Cbl-b with siRNAs to mimic their loss/inactivation sensitized neuronal cells to death promoted by NGF deprivation or DNA damage. One potential mechanism by which Cbl proteins might affect neuronal death is by regulation of apoptotic c-Jun N-terminal kinase (JNK) signaling. We demonstrate that Cbl pro-teins interact with the JNK pathway components mixed lineage kinase (MLK) 3 and POSH and that knockdown of Cbl proteins is sufficient to increase JNK pathway activity. Furthermore, expression of c-Cbl blocks the ability of MLKs to signal to downstream components of the kinase cascade leading to JNK activation and protects neuronal cells from death induced by MLKs, but not from downstream JNK activators. On the basis of these findings, we propose that Cbls suppress cell death in healthy neurons at least in part by inhibiting the ability of MLKs to activate JNK signaling. Apoptotic stimuli lead to loss of Cbl protein/activity, thereby removing a critical brake on JNK acti-vation and on cell death.

  7. Insulin signaling regulates mitochondrial function in pancreatic beta-cells.

    Directory of Open Access Journals (Sweden)

    Siming Liu

    Full Text Available Insulin/IGF-I signaling regulates the metabolism of most mammalian tissues including pancreatic islets. To dissect the mechanisms linking insulin signaling with mitochondrial function, we first identified a mitochondria-tethering complex in beta-cells that included glucokinase (GK, and the pro-apoptotic protein, BAD(S. Mitochondria isolated from beta-cells derived from beta-cell specific insulin receptor knockout (betaIRKO mice exhibited reduced BAD(S, GK and protein kinase A in the complex, and attenuated function. Similar alterations were evident in islets from patients with type 2 diabetes. Decreased mitochondrial GK activity in betaIRKOs could be explained, in part, by reduced expression and altered phosphorylation of BAD(S. The elevated phosphorylation of p70S6K and JNK1 was likely due to compensatory increase in IGF-1 receptor expression. Re-expression of insulin receptors in betaIRKO cells partially restored the stoichiometry of the complex and mitochondrial function. These data indicate that insulin signaling regulates mitochondrial function and have implications for beta-cell dysfunction in type 2 diabetes.

  8. KLF4 regulation in intestinal epithelial cell maturation

    International Nuclear Information System (INIS)

    The Krueppel-like factor 4 (KLF4) transcription factor suppresses tumorigenesis in gastrointestinal epithelium. Thus, its expression is decreased in gastric and colon cancers. Moreover, KLF4 regulates both differentiation and growth that is likely fundamental to its tumor suppressor activity. We dissected the expression of Klf4 in the normal mouse intestinal epithelium along the crypt-villus and cephalo-caudal axes. Klf4 reached its highest level in differentiated cells of the villus, with levels in the duodenum > jejunum > ileum, in inverse relation to the representation of goblet cells in these regions, the lineage previously linked to KLF4. In parallel, in vitro studies using HT29cl.16E and Caco2 colon cancer cell lines clarified that KLF4 increased coincident with differentiation along both the goblet and absorptive cell lineages, respectively, and that KLF4 levels also increased during differentiation induced by the short chain fatty acid butyrate, independently of cell fate. Moreover, we determined that lower levels of KLF4 expression in the proliferative compartment of the intestinal epithelium are regulated by the transcription factors TCF4 and SOX9, an effector and a target, respectively, of β-catenin/Tcf signaling, and independently of CDX2. Thus, reduced levels of KLF4 tumor suppressor activity in colon tumors may be driven by elevated β-catenin/Tcf signaling

  9. Vesicle Size Regulates Nanotube Formation in the Cell

    OpenAIRE

    Qian Peter Su; Wanqing Du; Qinghua Ji; Boxin Xue; Dong Jiang; Yueyao Zhu; Jizhong Lou; Li Yu; Yujie Sun

    2016-01-01

    Intracellular membrane nanotube formation and its dynamics play important roles for cargo transportation and organelle biogenesis. Regarding the regulation mechanisms, while much attention has been paid on the lipid composition and its associated protein molecules, effects of the vesicle size has not been studied in the cell. Giant unilamellar vesicles (GUVs) are often used for in vitro membrane deformation studies, but they are much larger than most intracellular vesicles and the in vitro st...

  10. Metric dynamics for membrane transformation through regulated cell proliferation

    OpenAIRE

    Ito, Hiroshi C.

    2016-01-01

    This study develops an equation for describing three-dimensional membrane transformation through proliferation of its component cells regulated by morphogen density distributions on the membrane. The equation is developed in a two-dimensional coordinate system mapped on the membrane, referred to as the membrane coordinates. When the membrane expands, the membrane coordinates expand in the same manner so that the membrane is invariant in the coordinates. In the membrane coordinate system, the ...

  11. Ets-1 regulates energy metabolism in cancer cells.

    Directory of Open Access Journals (Sweden)

    Meghan L Verschoor

    Full Text Available Cancer cells predominantly utilize glycolysis for ATP production even in the presence of abundant oxygen, an environment that would normally result in energy production through oxidative phosphorylation. Although the molecular mechanism for this metabolic switch to aerobic glycolysis has not been fully elucidated, it is likely that mitochondrial damage to the electron transport chain and the resulting increased production of reactive oxygen species are significant driving forces. In this study, we have investigated the role of the transcription factor Ets-1 in the regulation of mitochondrial function and metabolism. Ets-1 was over-expressed using a stably-incorporated tetracycline-inducible expression vector in the ovarian cancer cell line 2008, which does not express detectable basal levels of Ets-1 protein. Microarray analysis of the effects of Ets-1 over-expression in these ovarian cancer cells shows that Ets-1 up-regulates key enzymes involved in glycolysis and associated feeder pathways, fatty acid metabolism, and antioxidant defense. In contrast, Ets-1 down-regulates genes involved in the citric acid cycle, electron transport chain, and mitochondrial proteins. At the functional level, we have found that Ets-1 expression is directly correlated with cellular oxygen consumption whereby increased expression causes decreased oxygen consumption. Ets-1 over-expression also caused increased sensitivity to glycolytic inhibitors, as well as growth inhibition in a glucose-depleted culture environment. Collectively our findings demonstrate that Ets-1 is involved in the regulation of cellular metabolism and response to oxidative stress in ovarian cancer cells.

  12. Astrocyte Depletion Impairs Redox Homeostasis and Triggers Neuronal Loss in the Adult CNS

    Directory of Open Access Journals (Sweden)

    Bettina Schreiner

    2015-09-01

    Full Text Available Although the importance of reactive astrocytes during CNS pathology is well established, the function of astroglia in adult CNS homeostasis is less well understood. With the use of conditional, astrocyte-restricted protein synthesis termination, we found that selective paralysis of GFAP+ astrocytes in vivo led to rapid neuronal cell loss and severe motor deficits. This occurred while structural astroglial support still persisted and in the absence of any major microvascular damage. Whereas loss of astrocyte function did lead to microglial activation, this had no impact on the neuronal loss and clinical decline. Neuronal injury was caused by oxidative stress resulting from the reduced redox scavenging capability of dysfunctional astrocytes and could be prevented by the in vivo treatment with scavengers of reactive oxygen and nitrogen species (ROS/RNS. Our results suggest that the subpopulation of GFAP+ astrocytes maintain neuronal health by controlling redox homeostasis in the adult CNS.

  13. Prediction of epigenetically regulated genes in breast cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Loss, Leandro A; Sadanandam, Anguraj; Durinck, Steffen; Nautiyal, Shivani; Flaucher, Diane; Carlton, Victoria EH; Moorhead, Martin; Lu, Yontao; Gray, Joe W; Faham, Malek; Spellman, Paul; Parvin, Bahram

    2010-05-04

    Methylation of CpG islands within the DNA promoter regions is one mechanism that leads to aberrant gene expression in cancer. In particular, the abnormal methylation of CpG islands may silence associated genes. Therefore, using high-throughput microarrays to measure CpG island methylation will lead to better understanding of tumor pathobiology and progression, while revealing potentially new biomarkers. We have examined a recently developed high-throughput technology for measuring genome-wide methylation patterns called mTACL. Here, we propose a computational pipeline for integrating gene expression and CpG island methylation profles to identify epigenetically regulated genes for a panel of 45 breast cancer cell lines, which is widely used in the Integrative Cancer Biology Program (ICBP). The pipeline (i) reduces the dimensionality of the methylation data, (ii) associates the reduced methylation data with gene expression data, and (iii) ranks methylation-expression associations according to their epigenetic regulation. Dimensionality reduction is performed in two steps: (i) methylation sites are grouped across the genome to identify regions of interest, and (ii) methylation profles are clustered within each region. Associations between the clustered methylation and the gene expression data sets generate candidate matches within a fxed neighborhood around each gene. Finally, the methylation-expression associations are ranked through a logistic regression, and their significance is quantified through permutation analysis. Our two-step dimensionality reduction compressed 90% of the original data, reducing 137,688 methylation sites to 14,505 clusters. Methylation-expression associations produced 18,312 correspondences, which were used to further analyze epigenetic regulation. Logistic regression was used to identify 58 genes from these correspondences that showed a statistically signifcant negative correlation between methylation profles and gene expression in the

  14. Lentiviral-mediated administration of IL-25 in the CNS induces alternative activation of microglia

    DEFF Research Database (Denmark)

    Maiorino, C; Khorooshi, R; Ruffini, F;

    2013-01-01

    to modulate CNS myeloid cells, either infiltrating macrophages or resident microglia, towards an anti-inflammatory, tissue-protective phenotype, as testified by the increase in markers such as Arginase-1 (Arg1), Mannose receptor 1 (CD206) and Chitinase 3-like 3 (Ym1). As a consequence, neuroinflammation...... microglia in neurological disorders....

  15. Matrix rigidity regulates cancer cell growth and cellular phenotype.

    Directory of Open Access Journals (Sweden)

    Robert W Tilghman

    Full Text Available BACKGROUND: The mechanical properties of the extracellular matrix have an important role in cell growth and differentiation. However, it is unclear as to what extent cancer cells respond to changes in the mechanical properties (rigidity/stiffness of the microenvironment and how this response varies among cancer cell lines. METHODOLOGY/PRINCIPAL FINDINGS: In this study we used a recently developed 96-well plate system that arrays extracellular matrix-conjugated polyacrylamide gels that increase in stiffness by at least 50-fold across the plate. This plate was used to determine how changes in the rigidity of the extracellular matrix modulate the biological properties of tumor cells. The cell lines tested fall into one of two categories based on their proliferation on substrates of differing stiffness: "rigidity dependent" (those which show an increase in cell growth as extracellular rigidity is increased, and "rigidity independent" (those which grow equally on both soft and stiff substrates. Cells which grew poorly on soft gels also showed decreased spreading and migration under these conditions. More importantly, seeding the cell lines into the lungs of nude mice revealed that the ability of cells to grow on soft gels in vitro correlated with their ability to grow in a soft tissue environment in vivo. The lung carcinoma line A549 responded to culture on soft gels by expressing the differentiated epithelial marker E-cadherin and decreasing the expression of the mesenchymal transcription factor Slug. CONCLUSIONS/SIGNIFICANCE: These observations suggest that the mechanical properties of the matrix environment play a significant role in regulating the proliferation and the morphological properties of cancer cells. Further, the multiwell format of the soft-plate assay is a useful and effective adjunct to established 3-dimensional cell culture models.

  16. Regulations and guidelines governing stem cell based products: Clinical considerations

    Directory of Open Access Journals (Sweden)

    Bobby George

    2011-01-01

    Full Text Available The use of stem cells as medicines is a promising and upcoming area of research as they may be able to help the body to regenerate damaged or lost tissue in a host of diseases like Parkinson′s, multiple sclerosis, heart disease, liver disease, spinal cord damage, cancer and many more. Translating basic stem cell research into routine therapies is a complex multi-step process which entails the challenge related to managing the expected therapeutic benefits with the potential risks while complying with the existing regulations and guidelines. While in the United States (US and European Union (EU regulations are in place, in India, we do not have a well-defined regulatory framework for "stem cell based products (SCBP". There are several areas that need to be addressed as it is quite different from that of pharmaceuticals. These range from establishing batch consistency, product stability to product safety and efficacy through pre-clinical, clinical studies and marketing authorization. This review summarizes the existing regulations/guidelines in US, EU, India, and the associated challenges in developing SCBP with emphasis on clinical aspects.

  17. Changed iron regulation in scrapie-infected neuroblastoma cells.

    Science.gov (United States)

    Fernaeus, Sandra; Hälldin, Jonas; Bedecs, Katarina; Land, Tiit

    2005-02-18

    Prion diseases are characterized by the conversion of the normal cellular prion protein PrP(C) into a pathogenic isoform, PrP(Sc). The mechanisms involved in neuronal cell death in prion diseases are largely unknown, but accumulating evidence has demonstrated oxidative impairment along with metal imbalances in scrapie-infected brains. In this study, we report changes in cellular iron metabolism in scrapie-infected mouse neuroblastoma N2a cells (ScN2a). We detected twofold lower total cellular iron and calcein-chelatable cytosolic labile iron pool (LIP) in ScN2a cells as compared to the N2a cells. We also measured in ScN2a cells significantly lower activities of iron regulatory proteins 1 and 2 (IRP1 and IRP2, respectively), regulators of cellular iron by sensing cytosolic free iron levels and controlling posttranscriptionally the expression of the major iron transport protein transferrin receptor 1 (TfR1) and the iron sequestration protein ferritin. IRP1 and IRP2 protein levels were decreased by 40% and 50%, respectively, in ScN2a cells. TfR1 protein levels were fourfold reduced and ferritin levels were threefold reduced in ScN2a cells. TfR1 and ferritin mRNA levels were significantly reduced in ScN2a cells. ScN2a cells responded normally to iron and iron chelator treatment with respect to the activities of IRP1 and IRP2, and biosynthesis of TfR1 and ferritin. However, the activities of IRP1 and IRP2, and protein levels of TfR1 and ferritin, were still significantly lower in iron-depleted ScN2a cells as compared to the N2a cells, suggesting lower need for iron in ScN2a cells. Our results demonstrate that scrapie infection leads to changes in cellular iron metabolism, affecting both total cellular and cytosolic free iron, and the activities and expression of major regulators of cellular iron homeostasis. PMID:15710243

  18. Neuropeptides, via specific receptors, regulate T cell adhesion to fibronectin.

    Science.gov (United States)

    Levite, M; Cahalon, L; Hershkoviz, R; Steinman, L; Lider, O

    1998-01-15

    The ability of T cells to adhere to and interact with components of the blood vessel walls and the extracellular matrix is essential for their extravasation and migration into inflamed sites. We have found that the beta1 integrin-mediated adhesion of resting human T cells to fibronectin, a major glycoprotein component of the extracellular matrix, is induced by physiologic concentrations of three neuropeptides: calcitonin gene-related protein (CGRP), neuropeptide Y, and somatostatin; each acts via its own specific receptor on the T cell membrane. In contrast, substance P (SP), which coexists with CGRP in the majority of peripheral endings of sensory nerves, including those innervating the lymphoid organs, blocks T cell adhesion to fibronectin when induced by CGRP, neuropeptide Y, somatostatin, macrophage inflammatory protein-1beta, and PMA. Inhibition of T cell adhesion was obtained both by the intact SP peptide and by its 1-4 N-terminal and its 4-11, 5-11, and 6-11 C-terminal fragments, used at similar nanomolar concentrations. The inhibitory effects of the parent SP peptide and its fragments were abrogated by an SP NK-1 receptor antagonist, suggesting they all act through the same SP NK-1 receptor. These findings suggest that neuropeptides, by activating their specific T cell-expressed receptors, can provide the T cells with both positive (proadhesive) and negative (antiadhesive) signals and thereby regulate their function. Thus, neuropeptides may influence diverse physiologic processes involving integrins, including leukocyte-mediated migration and inflammation. PMID:9551939

  19. Laminin 5 regulates polycystic kidney cell proliferation and cyst formation.

    Science.gov (United States)

    Joly, Dominique; Berissi, Sophie; Bertrand, Amélie; Strehl, Laetitia; Patey, Natacha; Knebelmann, Bertrand

    2006-09-29

    Renal cyst formation is the hallmark of autosomal dominant polycystic kidney disease (ADPKD). ADPKD cyst-lining cells have an increased proliferation rate and are surrounded by an abnormal extracellular matrix (ECM). We have previously shown that Laminin 5 (Ln-5, a alpha(3)beta(3)gamma(2) trimer) is aberrantly expressed in the pericystic ECM of ADPKD kidneys. We report that ADPKD cells in primary cultures produce and secrete Ln-5 that is incorporated to the pericystic ECM in an in vitro model of cystogenesis. In monolayers, purified Ln-5 induces ERK activation and proliferation of ADPKD cells, whereas upon epidermal growth factor stimulation blocking endogenously produced Ln-5 with anti-gamma(2) chain antibody reduces the sustained ERK activation and inhibits proliferation. In three-dimensional gel culture, addition of purified Ln-5 stimulates cell proliferation and cyst formation, whereas blocking endogenous Ln-5 strongly inhibits cyst formation. Ligation of alpha(6)beta(4) integrin, a major Ln-5 receptor aberrantly expressed by ADPKD cells, induces beta(4) integrin phosphorylation, ERK activation, cell proliferation, and cyst formation. These findings indicate that Ln-5 is an important regulator of ADPKD cell proliferation and cystogenesis and suggest that Ln-5 gamma(2) chain and Ln-5-alpha(6)beta(4) integrin interaction both contribute to these phenotypic changes. PMID:16870608

  20. Clearance of an immunosuppressive virus from the CNS coincides with immune reanimation and diversification

    Directory of Open Access Journals (Sweden)

    McGavern Dorian B

    2007-06-01

    Full Text Available Abstract Once a virus infection establishes persistence in the central nervous system (CNS, it is especially difficult to eliminate from this specialized compartment. Therefore, it is of the utmost importance to fully understand scenarios during which a persisting virus is ultimately purged from the CNS by the adaptive immune system. Such a scenario can be found following infection of adult mice with an immunosuppressive variant of lymphocytic choriomeningitis virus (LCMV referred to as clone 13. In this study we demonstrate that following intravenous inoculation, clone 13 rapidly infected peripheral tissues within one week, but more slowly inundated the entire brain parenchyma over the course of a month. During the establishment of persistence, we observed that genetically tagged LCMV-specific cytotoxic T lymphocytes (CTL progressively lost function; however, the severity of this loss in the CNS was never as substantial as that observed in the periphery. One of the most impressive features of this model system is that the peripheral T cell response eventually regains functionality at ~60–80 days post-infection, and this was associated with a rapid decline in virus from the periphery. Coincident with this "reanimation phase" was a massive influx of CD4 T and B cells into the CNS and a dramatic reduction in viral distribution. In fact, olfactory bulb neurons served as the last refuge for the persisting virus, which was ultimately purged from the CNS within 200 days post-infection. These data indicate that a functionally revived immune response can prevail over a virus that establishes widespread presence both in the periphery and brain parenchyma, and that therapeutic enhancement of an existing response could serve as an effective means to thwart long term CNS persistence.

  1. Superficial siderosis of the CNS. MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Akira; Matsuo, Yoshiaki; Kato, Akira; Kudo, Sho [Saga Medical School, Nabeshima (Japan); Matsumoto, Shunichi

    1997-11-01

    Six cases of superficial siderosis of the CNS are reported here. There were 4 men and 2 women, whose ages ranged from 25 to 69 years. The clinical presentations included bilateral sensorineural hearing loss (6), cerebellar ataxia (4), and myelopathy (2). Typical hypointense rims were observed over the brain surface on T2-weighted images. Five of the 6 patients had atrophy of the superior cerebellar vermis. The spinal cord was involved in 5 of the 6 patients. On T1-weighted images, hyperintense rims were demonstrated over the brain surface in 3 of the 6 patients. This finding has not been previously reported. (author)

  2. The Arabidopsis synaptotagmin SYTA regulates the cell-to-cell movement of diverse plant viruses

    Directory of Open Access Journals (Sweden)

    Asako eUchiyama

    2014-11-01

    Full Text Available Synaptotagmins are a large gene family in animals that have been extensively characterized due to their role as calcium sensors to regulate synaptic vesicle exocytosis and endocytosis in neurons, and dense core vesicle exocytosis for hormone secretion from neuroendocrine cells. Thought to be exclusive to animals, synaptotagmins have recently been characterized in Arabidopsis thaliana, in which they comprise a five gene family. Using infectivity and leaf-based functional assays, we have shown that Arabidopsis SYTA regulates endocytosis and marks an endosomal vesicle recycling pathway to regulate movement protein-mediated trafficking of the Begomovirus Cabbage leaf curl virus (CaLCuV and the Tobamovirus Tobacco mosaic virus (TMV through plasmodesmata (Lewis and Lazarowitz, 2010. To determine whether SYTA has a central role in regulating the cell-to-cell trafficking of a wider range of diverse plant viruses, we extended our studies here to examine the role of SYTA in the cell-to-cell movement of additional plant viruses that employ different modes of movement, namely the Potyvirus Turnip mosaic virus (TuMV, the Caulimovirus Cauliflower mosaic virus (CaMV and the Tobamovirus Turnip vein clearing virus (TVCV, which in contrast to TMV does efficiently infect Arabidopsis. We found that both TuMV and TVCV systemic infection, and the cell-to-cell trafficking of the their movement proteins, were delayed in the Arabidopsis Col-0 syta-1 knockdown mutant. In contrast, CaMV systemic infection was not inhibited in syta-1. Our studies show that SYTA is a key regulator of plant virus intercellular movement, being necessary for the ability of diverse cell-to-cell movement proteins encoded by Begomoviruses (CaLCuV MP, Tobamoviruses (TVCV and TMV 30K protein and Potyviruses (TuMV P3N-PIPO to alter PD and thereby mediate virus cell-to-cell spread.

  3. The Drosophila actin regulator ENABLED regulates cell shape and orientation during gonad morphogenesis.

    Directory of Open Access Journals (Sweden)

    Hiroko Sano

    Full Text Available Organs develop distinctive morphologies to fulfill their unique functions. We used Drosophila embryonic gonads as a model to study how two different cell lineages, primordial germ cells (PGCs and somatic gonadal precursors (SGPs, combine to form one organ. We developed a membrane GFP marker to image SGP behaviors live. These studies show that a combination of SGP cell shape changes and inward movement of anterior and posterior SGPs leads to the compaction of the spherical gonad. This process is disrupted in mutants of the actin regulator, enabled (ena. We show that Ena coordinates these cell shape changes and the inward movement of the SGPs, and Ena affects the intracellular localization of DE-cadherin (DE-cad. Mathematical simulation based on these observations suggests that changes in DE-cad localization can generate the forces needed to compact an elongated structure into a sphere. We propose that Ena regulates force balance in the SGPs by sequestering DE-cad, leading to the morphogenetic movement required for gonad compaction.

  4. Copper as a key regulator of cell signalling pathways.

    Science.gov (United States)

    Grubman, Alexandra; White, Anthony R

    2014-05-22

    Copper is an essential element in many biological processes. The critical functions associated with copper have resulted from evolutionary harnessing of its potent redox activity. This same property also places copper in a unique role as a key modulator of cell signal transduction pathways. These pathways are the complex sequence of molecular interactions that drive all cellular mechanisms and are often associated with the interplay of key enzymes including kinases and phosphatases but also including intracellular changes in pools of smaller molecules. A growing body of evidence is beginning to delineate the how, when and where of copper-mediated control over cell signal transduction. This has been driven by research demonstrating critical changes to copper homeostasis in many disorders including cancer and neurodegeneration and therapeutic potential through control of disease-associated cell signalling changes by modulation of copper-protein interactions. This timely review brings together for the first time the diverse actions of copper as a key regulator of cell signalling pathways and discusses the potential strategies for controlling disease-associated signalling processes using copper modulators. It is hoped that this review will provide a valuable insight into copper as a key signal regulator and stimulate further research to promote our understanding of copper in disease and therapy.

  5. Regulation of. beta. -cell glucose transporter gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ling; Alam, Tausif; Johnson, J.H.; Unger, R.H. (Univ. of Texas Southwestern Medical Center, Dallas (USA) Department of Veterans Affairs Medical Center, Dallas, TX (USA)); Hughes, S.; Newgard, C.B. (Univ. of Texas Southwestern Medical Center, Dallas (USA))

    1990-06-01

    It has been postulated that a glucose transporter of {beta} cells (GLUT-2) may be important in glucose-stimulated insulin secretion. To determine whether this transporter is constitutively expressed or regulated, the authors subjected conscious unrestrained Wistar rats to perturbations in glucose homeostasis and quantitated {beta}-cell GLUT-2 mRNA by in situ hybridization. After 3 hr of hypoglycemia, GLUT-2 and proinsulin mRNA signal densities were reduced by 25% of the level in control rats. After 4 days, GLUT-2 and proinsulin mRNA densities were reduced by 85% and 65%, respectively. After 12 days of hypoglycemia, the K{sub m} for 3-O-methyl-D-glucose transport in isolated rat islets, normally 18-20 mM, was 2.5 mM. This provides functional evidence of a profound reduction of high K{sub m} glucose transporter in {beta} cells. In contrast, GLUT-2 was only slightly reduced by hypoglycemia in liver. To determine the effect of prolonged hyperglycemia, they also infused animals with 50% (wt/vol) glucose for 5 days. Hyperglycemic clamping increased GLUT-2 mRNA by 46% whereas proinsulin mRNA doubled. They conclude that GLUT-2 expression in {beta} cells, but not liver, is subject to regulation by certain perturbations in blood glucose homeostasis.

  6. Regulation of β-cell glucose transporter gene expression

    International Nuclear Information System (INIS)

    It has been postulated that a glucose transporter of β cells (GLUT-2) may be important in glucose-stimulated insulin secretion. To determine whether this transporter is constitutively expressed or regulated, the authors subjected conscious unrestrained Wistar rats to perturbations in glucose homeostasis and quantitated β-cell GLUT-2 mRNA by in situ hybridization. After 3 hr of hypoglycemia, GLUT-2 and proinsulin mRNA signal densities were reduced by 25% of the level in control rats. After 4 days, GLUT-2 and proinsulin mRNA densities were reduced by 85% and 65%, respectively. After 12 days of hypoglycemia, the Km for 3-O-methyl-D-glucose transport in isolated rat islets, normally 18-20 mM, was 2.5 mM. This provides functional evidence of a profound reduction of high Km glucose transporter in β cells. In contrast, GLUT-2 was only slightly reduced by hypoglycemia in liver. To determine the effect of prolonged hyperglycemia, they also infused animals with 50% (wt/vol) glucose for 5 days. Hyperglycemic clamping increased GLUT-2 mRNA by 46% whereas proinsulin mRNA doubled. They conclude that GLUT-2 expression in β cells, but not liver, is subject to regulation by certain perturbations in blood glucose homeostasis

  7. From stem cell to erythroblast: regulation of red cell production at multiple levels by multiple hormones.

    Science.gov (United States)

    Lodish, Harvey; Flygare, Johan; Chou, Song

    2010-07-01

    This article reviews the regulation of production of red blood cells at several levels: (1) the ability of erythropoietin and adhesion to a fibronectin matrix to stimulate the rapid production of red cells by inducing terminal proliferation and differentiation of committed erythroid CFU-E progenitors; (2) the regulated expansion of the pool of earlier BFU-E erythroid progenitors by glucocorticoids and other factors that occurs during chronic anemia or inflammation; and (3) the expansion of thehematopoietic cell pool to produce more progenitors of all hematopoietic lineages.

  8. miR-526a regulates apoptotic cell growth in human carcinoma cells.

    Science.gov (United States)

    Yang, Xiaoli; Wang, Cui; Xu, Changzhi; Yan, Zhifeng; Wei, Congwen; Guan, Kai; Ma, Shengli; Cao, Ye; Liu, Liping; Zou, Deyong; He, Xiang; Zhang, Buchang; Ma, Qingjun; Zheng, Zirui

    2015-09-01

    MicroRNAs (miRNAs) play vital roles in the regulation of cell cycle, cell growth, apoptosis, and tumorigenesis. Our previous studies showed that miR-526a positively regulated innate immune response by suppressing CYLD expression, however, the functional relevance of miR-526a expression and cell growth remains to be evaluated. In this study, miR-526a overexpression was found to promote cancer cell proliferation, migration, and anchor-independent colony formation. The molecular mechanism(s) of miR-526a-mediated growth stimulation is associated with rapid cell cycle progression and inhibition of cell apoptosis by targeting CYLD. Taken together, these results provide evidence to show the stimulatory role of miR-526a in tumor migration and invasion through modulation of the canonical NF-κB signaling pathway. PMID:26002288

  9. Chromokinesin: Kinesin superfamily regulating cell division through chromosome and spindle.

    Science.gov (United States)

    Zhong, Ai; Tan, Fu-Qing; Yang, Wan-Xi

    2016-09-01

    Material transportation is essential for appropriate cellular morphology and functions, especially during cell division. As a motor protein moving along microtubules, kinesin has several intracellular functions. Many kinesins play important roles in chromosome condensation and separation and spindle organization during the cell cycle. Some of them even can directly bind to chromosomes, as a result, these proteins are called chromokinesins. Kinesin-4 and kinesin-10 family are two major families of chromokinesin and many members can regulate some processes, both in mitosis and meiosis. Their functions have been widely studied. Here, we summarize current knowledge about known chromokinesins and introduce their intracellular features in accordance with different families. Furthermore, we have also introduced some new-found but unconfirmed kinesins which may have a relationship with chromosomes or the cell cycle. PMID:27196062

  10. Hormonal regulation of the hypothalamic melanocortin system

    OpenAIRE

    Kim, Jung D.; Leyva, Stephanie; Diano, Sabrina

    2014-01-01

    Regulation of energy homeostasis is fundamental for life. In animal species and humans, the Central Nervous System (CNS) plays a critical role in such regulation by integrating peripheral signals and modulating behavior and the activity of peripheral organs. A precise interplay between CNS and peripheral signals is necessary for the regulation of food intake and energy expenditure in the maintenance of energy balance. Within the CNS, the hypothalamus is a critical center for monitoring, proce...

  11. Protein phosphatase 2A isotypes regulate cell surface expression of the T cell receptor

    DEFF Research Database (Denmark)

    Lauritsen, Jens Peter Holst; Menné, C; Kastrup, J;

    2001-01-01

    The mechanisms underlying T cell receptor (TCR) down-regulation have been extensively studied during the last decade. Whereas the importance of phosphorylation in this process has been established, it is less certain whether dephosphorylation plays a role in TCR down-regulation. In this study, we...... show that inhibition of the serine/threonine protein phosphatase PP2A family had a biphasic effect on TCR expression. Thus, low concentrations of PP2A inhibitors induced TCR down-regulation, whereas higher concentrations of PP2A inhibitors induced TCR up-regulation. The effect of PP2A inhibition was...... independent of phosphorylation of the CD3gamma endocytosis motif. Whereas TCR down-regulation was caused by a partial inhibition of exocytosis, TCR up-regulation was caused by an inhibition of endocytosis. The effects on exocytosis and endocytosis were not restricted to the TCR, indicating a more general...

  12. Wnt inhibitory factor-1 regulates glioblastoma cell cycle and proliferation.

    Science.gov (United States)

    Wu, Jun; Fang, Jiasheng; Yang, Zhuanyi; Chen, Fenghua; Liu, Jingfang; Wang, Yanjin

    2012-10-01

    Wnt proteins are powerful regulators of cell proliferation and differentiation, and activation of the Wnt signalling pathway is involved in the pathogenesis of several types of human tumours. Wnt inhibitory factor-1 (WIF-1) acts as a Wnt antagonist and tumour suppressor. Previous studies have shown that reducing expression of the WIF-1 gene aberrantly activates Wnt signalling and induces the development of certain types of cancers. In the present study, we examined the expression of WIF-1 in human primary glioblastoma multiforme (GBM) tumours. Studies using semiquantitative reverse transcription-polymerase chain reaction and immunohistochemical analysis revealed that WIF-1 expression is lower in human GBM than in normal brain tissue. To clarify the role of WIF-1, we transfected U251 human glioblastoma-derived cells, which do not express WIF-1, with the pcDNA3.1-WIF1 vector to restore WIF-1 expression. The results of cell proliferation, colony formation and apoptosis assays, as well as flow cytometry, indicate that exogenous WIF-1 has no effect on U251 cell apoptosis, but does arrest cells at the G(0)/G(1) phase and inhibit cell growth. Collectively, our data suggest that WIF-1 is a potent inhibitor of GBM growth. PMID:22901505

  13. Estrogen regulation of TRPM8 expression in breast cancer cells

    Directory of Open Access Journals (Sweden)

    Sevestre Henri

    2010-05-01

    Full Text Available Abstract Background The calcium-permeable cation channel TRPM8 (melastatin-related transient receptor potential member 8 is over-expressed in several cancers. The present study aimed at investigating the expression, function and potential regulation of TRPM8 channels by ER alpha (estrogen receptor alpha in breast cancer. Methods RT-PCR, Western blot, immuno-histochemical, and siRNA techniques were used to investigate TRPM8 expression, its regulation by estrogen receptors, and its expression in breast tissue. To investigate the channel activity in MCF-7 cells, we used the whole cell patch clamp and the calcium imaging techniques. Results TRPM8 channels are expressed at both mRNA and protein levels in the breast cancer cell line MCF-7. Bath application of the potent TRPM8 agonist Icilin (20 μM induced a strong outwardly rectifying current at depolarizing potentials, which is associated with an elevation of cytosolic calcium concentration, consistent with established TRPM8 channel properties. RT-PCR experiments revealed a decrease in TRPM8 mRNA expression following steroid deprivation for 48 and 72 hours. In steroid deprived medium, addition of 17-beta-estradiol (E2, 10 nM increased both TRPM8 mRNA expression and the number of cells which respond to Icilin, but failed to affect the Ca2+ entry amplitude. Moreover, silencing ERα mRNA expression with small interfering RNA reduced the expression of TRPM8. Immuno-histochemical examination of the expression of TRPM8 channels in human breast tissues revealed an over-expression of TRPM8 in breast adenocarcinomas, which is correlated with estrogen receptor positive (ER+ status of the tumours. Conclusion Taken together, these results show that TRPM8 channels are expressed and functional in breast cancer and that their expression is regulated by ER alpha.

  14. Heregulin, a new regulator of telomere length in human cells.

    Science.gov (United States)

    Menendez, Javier A; Rubio, Miguel A; Campisi, Judith; Lupu, Ruth

    2015-11-24

    The growth factor heregulin (HRG) promotes breast cancer (BC) tumorigenesis and metastasis and differentially modulates BC cell responses to DNA-damaging agents via its dual extracellular and nuclear localization. Given the central role of telomere dysfunction to drive carcinogenesis and to alter the chemotherapeutic profile of transformed cells, we hypothesized that an unanticipated nuclear function of HRG might be to regulate telomere length. Engineered overexpression of the HRGβ2 isoform in non-aggressive, HRG-negative MCF-7 BC cells resulted in a significant shortening of telomeres (up to 1.3 kb) as measured by Southern blotting of telomere terminal restriction fragments. Conversely, antisense-mediated suppression of HRGβ2 in highly aggressive, HRG-overexpressing MDA-MB-231 and Hs578T cells increased telomere length up to 3.0 kb. HRGβ2 overexpression promoted a marked upregulation of telomere-binding protein 2 (TRF2) protein expression, whereas its knockdown profoundly decreased TRF2 expression. Double staining of endogenous HRGβ2 with telomere-specific peptide nucleic acid probe/fluorescence in situ hybridization (PNA/FISH) revealed the partial localization of HRG at the chromosome ends. Moreover, a predominantly nucleoplasmic staining pattern of endogenous HRGβ2 appeared to co-localize with TRF2 and, concomitantly with RAP1, a telomere regulator that specifically interacts with TRF2. Small interfering RNA-mediated knockdown of HRG decreased the expression of TRF2 and RAP1, decreased their presence at chromosome ends, and coincidentally resulted in the formation of longer telomeres. This study uncovers a new function for HRGβ2 in controlling telomere length, in part due to its ability to regulate and interact with the telomere-associated proteins TRF2 and RAP1.

  15. Wnt/β-catenin signaling regulates cancer stem cells in lung cancer A549 cells

    International Nuclear Information System (INIS)

    Wnt/β-catenin signaling plays an important role not only in cancer, but also in cancer stem cells. In this study, we found that β-catenin and OCT-4 was highly expressed in cisplatin (DDP) selected A549 cells. Stimulating A549 cells with lithium chloride (LiCl) resulted in accumulation of β-catenin and up-regulation of a typical Wnt target gene cyclin D1. This stimulation also significantly enhanced proliferation, clone formation, migration and drug resistance abilities in A549 cells. Moreover, the up-regulation of OCT-4, a stem cell marker, was observed through real-time PCR and Western blotting. In a reverse approach, we inhibited Wnt signaling by knocking down the expression of β-catenin using RNA interference technology. This inhibition resulted in down-regulation of the Wnt target gene cyclin D1 as well as the proliferation, clone formation, migration and drug resistance abilities. Meanwhile, the expression of OCT-4 was reduced after the inhibition of Wnt/β-catenin signaling. Taken together, our study provides strong evidence that canonical Wnt signaling plays an important role in lung cancer stem cell properties, and it also regulates OCT-4, a lung cancer stem cell marker.

  16. Aquaporin 2-increased renal cell proliferation is associated with cell volume regulation.

    Science.gov (United States)

    Di Giusto, Gisela; Flamenco, Pilar; Rivarola, Valeria; Fernández, Juan; Melamud, Luciana; Ford, Paula; Capurro, Claudia

    2012-12-01

    We have previously demonstrated that in renal cortical collecting duct cells (RCCD(1)) the expression of the water channel Aquaporin 2 (AQP2) raises the rate of cell proliferation. In this study, we investigated the mechanisms involved in this process, focusing on the putative link between AQP2 expression, cell volume changes, and regulatory volume decrease activity (RVD). Two renal cell lines were used: WT-RCCD(1) (not expressing aquaporins) and AQP2-RCCD(1) (transfected with AQP2). Our results showed that when most RCCD(1) cells are in the G(1)-phase (unsynchronized), the blockage of barium-sensitive K(+) channels implicated in rapid RVD inhibits cell proliferation only in AQP2-RCCD(1) cells. Though cells in the S-phase (synchronized) had a remarkable increase in size, this enhancement was higher and was accompanied by a significant down-regulation in the rapid RVD response only in AQP2-RCCD(1) cells. This decrease in the RVD activity did not correlate with changes in AQP2 function or expression, demonstrating that AQP2-besides increasing water permeability-would play some other role. These observations together with evidence implying a cell-sizing mechanism that shortens the cell cycle of large cells, let us to propose that during nutrient uptake, in early G(1), volume tends to increase but it may be efficiently regulated by an AQP2-dependent mechanism, inducing the rapid activation of RVD channels. This mechanism would be down-regulated when volume needs to be increased in order to proceed into the S-phase. Therefore, during cell cycle, a coordinated modulation of the RVD activity may contribute to accelerate proliferation of cells expressing AQP2. PMID:22786728

  17. CNS myelin wrapping is driven by actin disassembly.

    Science.gov (United States)

    Zuchero, J Bradley; Fu, Meng-Meng; Sloan, Steven A; Ibrahim, Adiljan; Olson, Andrew; Zaremba, Anita; Dugas, Jason C; Wienbar, Sophia; Caprariello, Andrew V; Kantor, Christopher; Leonoudakis, Dmitri; Leonoudakus, Dmitri; Lariosa-Willingham, Karen; Kronenberg, Golo; Gertz, Karen; Soderling, Scott H; Miller, Robert H; Barres, Ben A

    2015-07-27

    Myelin is essential in vertebrates for the rapid propagation of action potentials, but the molecular mechanisms driving its formation remain largely unknown. Here we show that the initial stage of process extension and axon ensheathment by oligodendrocytes requires dynamic actin filament assembly by the Arp2/3 complex. Unexpectedly, subsequent myelin wrapping coincides with the upregulation of actin disassembly proteins and rapid disassembly of the oligodendrocyte actin cytoskeleton and does not require Arp2/3. Inducing loss of actin filaments drives oligodendrocyte membrane spreading and myelin wrapping in vivo, and the actin disassembly factor gelsolin is required for normal wrapping. We show that myelin basic protein, a protein essential for CNS myelin wrapping whose role has been unclear, is required for actin disassembly, and its loss phenocopies loss of actin disassembly proteins. Together, these findings provide insight into the molecular mechanism of myelin wrapping and identify it as an actin-independent form of mammalian cell motility.

  18. Signal integration by Ca2+ regulates intestinal stem cell activity

    Science.gov (United States)

    Deng, Hansong; Gerencser, Akos A.; Jasper, Heinrich

    2015-01-01

    Summary Somatic stem cells (SCs) maintain tissue homeostasis by dynamically adjusting proliferation and differentiation in response to stress and metabolic cues. Here, we identify Ca2+ signaling as a central regulator of intestinal SC (ISC) activity in Drosophila. We find that dietary L-glutamate stimulates ISC division and gut growth. The metabotropic glutamate receptor (mGluR) is required in ISCs for this response and for an associated modulation of cytosolic Ca2+ oscillations that results in sustained high cytosolic Ca2+ concentrations. High cytosolic Ca2+ induces ISC proliferation by regulating Calcineurin and CREB - regulated transcriptional co-activator (CRTC). In response to a wide range of dietary and stress stimuli, ISCs reversibly transition between Ca2+ oscillation states that represent poised or activated modes of proliferation, respectively. We propose that the dynamic regulation of intracellular Ca2+ levels allows effective integration of diverse mitogenic signals in ISCs to tailor their proliferative activity to the needs of the tissue. PMID:26633624

  19. Ghrelin regulates cell cycle-related gene expression in cultured hippocampal neural stem cells.

    Science.gov (United States)

    Chung, Hyunju; Park, Seungjoon

    2016-08-01

    We have previously demonstrated that ghrelin stimulates the cellular proliferation of cultured adult rat hippocampal neural stem cells (NSCs). However, little is known about the molecular mechanisms by which ghrelin regulates cell cycle progression. The purpose of this study was to investigate the potential effects of ghrelin on cell cycle regulatory molecules in cultured hippocampal NSCs. Ghrelin treatment increased proliferation assessed by CCK-8 proliferation assay. The expression levels of proliferating cell nuclear antigen and cell division control 2, well-known cell-proliferating markers, were also increased by ghrelin. Fluorescence-activated cell sorting analysis revealed that ghrelin promoted progression of cell cycle from G0/G1 to S phase, whereas this progression was attenuated by the pretreatment with specific inhibitors of MEK/extracellular signal-regulated kinase 1/2, phosphoinositide 3-kinase/Akt, mammalian target of rapamycin, and janus kinase 2/signal transducer and activator of transcription 3. Ghrelin-induced proliferative effect was associated with increased expression of E2F1 transcription factor in the nucleus, as determined by Western blotting and immunofluorescence. We also found that ghrelin caused an increase in protein levels of positive regulators of cell cycle, such as cyclin A and cyclin-dependent kinase (CDK) 2. Moreover, p27(KIP1) and p57(KIP2) protein levels were reduced when cell were exposed to ghrelin, suggesting downregulation of CDK inhibitors may contribute to proliferative effect of ghrelin. Our data suggest that ghrelin targets both cell cycle positive and negative regulators to stimulate proliferation of cultured hippocampal NSCs. PMID:27325242

  20. RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Houcai; Yu, Jing; Zhang, Lixia; Xiong, Yuanyuan; Chen, Shuying; Xing, Haiyan; Tian, Zheng; Tang, Kejing; Wei, Hui; Rao, Qing; Wang, Min; Wang, Jianxiang, E-mail: wangjx@ihcams.ac.cn

    2014-04-18

    Highlights: • RPS27a expression was up-regulated in advanced-phase CML and AL patients. • RPS27a knockdown changed biological property of K562 and K562/G01 cells. • RPS27a knockdown affected Raf/MEK/ERK, P21 and BCL-2 signaling pathways. • RPS27a knockdown may be applicable for new combination therapy in CML patients. - Abstract: Ribosomal protein S27a (RPS27a) could perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The high expression level of RPS27a was reported in solid tumors, and we found that the expression level of RPS27a was up-regulated in advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL) patients. In this study, we explored the function of RPS27a in leukemia cells by using CML cell line K562 cells and its imatinib resistant cell line K562/G01 cells. It was observed that the expression level of RPS27a was high in K562 cells and even higher in K562/G01 cells. Further analysis revealed that RPS27a knockdown by shRNA in both K562 and K562G01 cells inhibited the cell viability, induced cell cycle arrest at S and G2/M phases and increased cell apoptosis induced by imatinib. Combination of shRNA with imatinib treatment could lead to more cleaved PARP and cleaved caspase-3 expression in RPS27a knockdown cells. Further, it was found that phospho-ERK(p-ERK) and BCL-2 were down-regulated and P21 up-regulated in RPS27a knockdown cells. In conclusion, RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells. It appears that drugs targeting RPS27a combining with tyrosine kinase inhibitor (TKI) might represent a novel therapy strategy in TKI resistant CML patients.

  1. Caspases regulate VAMP-8 expression and phagocytosis in dendritic cells.

    Science.gov (United States)

    Ho, Yong Hou Sunny; Cai, Deyu Tarika; Huang, Dachuan; Wang, Cheng Chun; Wong, Siew Heng

    2009-09-18

    During an inflammation and upon encountering pathogens, immature dendritic cells (DC) undergo a maturation process to become highly efficient in presenting antigens. This transition from immature to mature state is accompanied by various physiological, functional and morphological changes including reduction of caspase activity and inhibition of phagocytosis in the mature DC. Caspases are cysteine proteases which play essential roles in apoptosis, necrosis and inflammation. Here, we demonstrate that VAMP-8, (a SNARE protein of the early/late endosomes) which has been shown previously to inhibit phagocytosis in DC, is a substrate of caspases. Furthermore, we identified two putative conserved caspase recognition/cleavage sites on the VAMP-8 protein. Consistent with the up-regulation of VAMP-8 expression upon treatment with caspase inhibitor (CI), immature DC treated with CI exhibits lower phagocytosis activity. Thus, our results highlight the role of caspases in regulating VAMP-8 expression and subsequently phagocytosis during maturation of DC.

  2. Cell Adhesion Geometry Regulates Non-Random DNA Segregation and Asymmetric Cell Fates in Mouse Skeletal Muscle Stem Cells

    OpenAIRE

    Siham Yennek; Mithila Burute; Manuel Théry; Shahragim Tajbakhsh

    2014-01-01

    Cells of several metazoan species have been shown to non-randomly segregate their DNA such that older template DNA strands segregate to one daughter cell. The mechanisms that regulate this asymmetry remain undefined. Determinants of cell fate are polarized during mitosis and partitioned asymmetrically as the spindle pole orients during cell division. Chromatids align along the pole axis; therefore, it is unclear whether extrinsic cues that determine spindle pole position also promote non-rand...

  3. Cell Adhesion Geometry Regulates Non-Random DNA Segregation and Asymmetric Cell Fates in Mouse Skeletal Muscle Stem Cells

    OpenAIRE

    Yennek, Siham; Burute, Mithila; Théry, Manuel; Tajbakhsh, Shahragim

    2014-01-01

    International audience Cells of several metazoan species have been shown to non-randomly segregate their DNA such that older template DNA strands segregate to one daughter cell. The mechanisms that regulate this asymmetry remain undefined. Determinants of cell fate are polarized during mitosis and partitioned asymmetrically as the spindle pole orients during cell division. Chromatids align along the pole axis; therefore, it is unclear whether extrinsic cues that determine spindle pole posi...

  4. Cell adhesion geometry regulates non-random DNA segregation and asymmetric cell fates in mouse skeletal muscle stem cells.

    OpenAIRE

    Yennek, Siham; Burute, Mithila; Théry, Manuel; Tajbakhsh, Shahragim

    2014-01-01

    International audience Cells of several metazoan species have been shown to non-randomly segregate their DNA such that older template DNA strands segregate to one daughter cell. The mechanisms that regulate this asymmetry remain undefined. Determinants of cell fate are polarized during mitosis and partitioned asymmetrically as the spindle pole orients during cell division. Chromatids align along the pole axis; therefore, it is unclear whether extrinsic cues that determine spindle pole posi...

  5. Cell adhesion geometry regulates non-random DNA segregation and asymmetric cell fates in mouse skeletal muscle stem cells

    OpenAIRE

    Yennek, Siham; Burute, Mithila; Thery, Manuel

    2014-01-01

    Cells of several metazoan species have been shown to non-randomly segregate their DNA such that older template DNA strands segregate to one daughter cell. The mechanisms that regulate this asymmetry remain undefined. Determinants of cell fate are polarized during mitosis and partitioned asymmetrically as the spindle pole orients during cell division. Chromatids align along the pole axis; therefore, it is unclear whether extrinsic cues that determine spindle pole position also promote non-rand...

  6. Development of Novel In Vivo Chemical Probes to Address CNS Protein Kinase Involvement in Synaptic Dysfunction.

    Directory of Open Access Journals (Sweden)

    D Martin Watterson

    Full Text Available Serine-threonine protein kinases are critical to CNS function, yet there is a dearth of highly selective, CNS-active kinase inhibitors for in vivo investigations. Further, prevailing assumptions raise concerns about whether single kinase inhibitors can show in vivo efficacy for CNS pathologies, and debates over viable approaches to the development of safe and efficacious kinase inhibitors are unsettled. It is critical, therefore, that these scientific challenges be addressed in order to test hypotheses about protein kinases in neuropathology progression and the potential for in vivo modulation of their catalytic activity. Identification of molecular targets whose in vivo modulation can attenuate synaptic dysfunction would provide a foundation for future disease-modifying therapeutic development as well as insight into cellular mechanisms. Clinical and preclinical studies suggest a critical link between synaptic dysfunction in neurodegenerative disorders and the activation of p38αMAPK mediated signaling cascades. Activation in both neurons and glia also offers the unusual potential to generate enhanced responses through targeting a single kinase in two distinct cell types involved in pathology progression. However, target validation has been limited by lack of highly selective inhibitors amenable to in vivo use in the CNS. Therefore, we employed high-resolution co-crystallography and pharmacoinformatics to design and develop a novel synthetic, active site targeted, CNS-active, p38αMAPK inhibitor (MW108. Selectivity was demonstrated by large-scale kinome screens, functional GPCR agonist and antagonist analyses of off-target potential, and evaluation of cellular target engagement. In vitro and in vivo assays demonstrated that MW108 ameliorates beta-amyloid induced synaptic and cognitive dysfunction. A serendipitous discovery during co-crystallographic analyses revised prevailing models about active site targeting of inhibitors, providing insights

  7. Lsd1 restricts the number of germline stem cells by regulating multiple targets in escort cells.

    Directory of Open Access Journals (Sweden)

    Susan Eliazer

    2014-03-01

    Full Text Available Specialized microenvironments called niches regulate tissue homeostasis by controlling the balance between stem cell self-renewal and the differentiation of stem cell daughters. However the mechanisms that govern the formation, size and signaling of in vivo niches remain poorly understood. Loss of the highly conserved histone demethylase Lsd1 in Drosophila escort cells results in increased BMP signaling outside the cap cell niche and an expanded germline stem cell (GSC phenotype. Here we present evidence that loss of Lsd1 also results in gradual changes in escort cell morphology and their eventual death. To better characterize the function of Lsd1 in different cell populations within the ovary, we performed Chromatin immunoprecipitation coupled with massive parallel sequencing (ChIP-seq. This analysis shows that Lsd1 associates with a surprisingly limited number of sites in escort cells and fewer, and often, different sites in cap cells. These findings indicate that Lsd1 exhibits highly selective binding that depends greatly on specific cellular contexts. Lsd1 does not directly target the dpp locus in escort cells. Instead, Lsd1 regulates engrailed expression and disruption of engrailed and its putative downstream target hedgehog suppress the Lsd1 mutant phenotype. Interestingly, over-expression of engrailed, but not hedgehog, results in an expansion of GSC cells, marked by the expansion of BMP signaling. Knockdown of other potential direct Lsd1 target genes, not obviously linked to BMP signaling, also partially suppresses the Lsd1 mutant phenotype. These results suggest that Lsd1 restricts the number of GSC-like cells by regulating a diverse group of genes and provide further evidence that escort cell function must be carefully controlled during development and adulthood to ensure proper germline differentiation.

  8. Regulation of cell death receptor S-nitrosylation and apoptotic signaling by Sorafenib in hepatoblastoma cells.

    Science.gov (United States)

    Rodríguez-Hernández, A; Navarro-Villarán, E; González, R; Pereira, S; Soriano-De Castro, L B; Sarrias-Giménez, A; Barrera-Pulido, L; Álamo-Martínez, J M; Serrablo-Requejo, A; Blanco-Fernández, G; Nogales-Muñoz, A; Gila-Bohórquez, A; Pacheco, D; Torres-Nieto, M A; Serrano-Díaz-Canedo, J; Suárez-Artacho, G; Bernal-Bellido, C; Marín-Gómez, L M; Barcena, J A; Gómez-Bravo, M A; Padilla, C A; Padillo, F J; Muntané, J

    2015-12-01

    Nitric oxide (NO) plays a relevant role during cell death regulation in tumor cells. The overexpression of nitric oxide synthase type III (NOS-3) induces oxidative and nitrosative stress, p53 and cell death receptor expression and apoptosis in hepatoblastoma cells. S-nitrosylation of cell death receptor modulates apoptosis. Sorafenib is the unique recommended molecular-targeted drug for the treatment of patients with advanced hepatocellular carcinoma. The present study was addressed to elucidate the potential role of NO during Sorafenib-induced cell death in HepG2 cells. We determined the intra- and extracellular NO concentration, cell death receptor expression and their S-nitrosylation modifications, and apoptotic signaling in Sorafenib-treated HepG2 cells. The effect of NO donors on above parameters has also been determined. Sorafenib induced apoptosis in HepG2 cells. However, low concentration of the drug (10nM) increased cell death receptor expression, as well as caspase-8 and -9 activation, but without activation of downstream apoptotic markers. In contrast, Sorafenib (10 µM) reduced upstream apoptotic parameters but increased caspase-3 activation and DNA fragmentation in HepG2 cells. The shift of cell death signaling pathway was associated with a reduction of S-nitrosylation of cell death receptors in Sorafenib-treated cells. The administration of NO donors increased S-nitrosylation of cell death receptors and overall induction of cell death markers in control and Sorafenib-treated cells. In conclusion, Sorafenib induced alteration of cell death receptor S-nitrosylation status which may have a relevant repercussion on cell death signaling in hepatoblastoma cells.

  9. Acetylation modification regulates GRP78 secretion in colon cancer cells.

    Science.gov (United States)

    Li, Zongwei; Zhuang, Ming; Zhang, Lichao; Zheng, Xingnan; Yang, Peng; Li, Zhuoyu

    2016-01-01

    High glucose-regulated protein 78 (GRP78) expression contributes to the acquisition of a wide range of phenotypic cancer hallmarks, and the pleiotropic oncogenic functions of GRP78 may result from its diverse subcellular distribution. Interestingly, GRP78 has been reported to be secreted from solid tumour cells, participating in cell-cell communication in the tumour microenvironment. However, the mechanism underlying this secretion remains elusive. Here, we report that GRP78 is secreted from colon cancer cells via exosomes. Histone deacetylase (HDAC) inhibitors blocked GRP78 release by inducing its aggregation in the ER. Mechanistically, HDAC inhibitor treatment suppressed HDAC6 activity and led to increased GRP78 acetylation; acetylated GRP78 then bound to VPS34, a class III phosphoinositide-3 kinase, consequently preventing the sorting of GRP78 into multivesicular bodies (MVBs). Of note, we found that mimicking GRP78 acetylation by substituting the lysine at residue 633, one of the deacetylated sites of HDAC6, with a glutamine resulted in decreased GRP78 secretion and impaired tumour cell growth in vitro. Our study thus reveals a hitherto-unknown mechanism of GRP78 secretion and may also provide implications for the therapeutic use of HDAC inhibitors. PMID:27460191

  10. Acetylation modification regulates GRP78 secretion in colon cancer cells

    Science.gov (United States)

    Li, Zongwei; Zhuang, Ming; Zhang, Lichao; Zheng, Xingnan; Yang, Peng; Li, Zhuoyu

    2016-01-01

    High glucose-regulated protein 78 (GRP78) expression contributes to the acquisition of a wide range of phenotypic cancer hallmarks, and the pleiotropic oncogenic functions of GRP78 may result from its diverse subcellular distribution. Interestingly, GRP78 has been reported to be secreted from solid tumour cells, participating in cell-cell communication in the tumour microenvironment. However, the mechanism underlying this secretion remains elusive. Here, we report that GRP78 is secreted from colon cancer cells via exosomes. Histone deacetylase (HDAC) inhibitors blocked GRP78 release by inducing its aggregation in the ER. Mechanistically, HDAC inhibitor treatment suppressed HDAC6 activity and led to increased GRP78 acetylation; acetylated GRP78 then bound to VPS34, a class III phosphoinositide-3 kinase, consequently preventing the sorting of GRP78 into multivesicular bodies (MVBs). Of note, we found that mimicking GRP78 acetylation by substituting the lysine at residue 633, one of the deacetylated sites of HDAC6, with a glutamine resulted in decreased GRP78 secretion and impaired tumour cell growth in vitro. Our study thus reveals a hitherto-unknown mechanism of GRP78 secretion and may also provide implications for the therapeutic use of HDAC inhibitors. PMID:27460191

  11. Regulation of cell survival by Na+/H+ exchanger-1.

    Science.gov (United States)

    Schelling, Jeffrey R; Abu Jawdeh, Bassam G

    2008-09-01

    Na(+)/H(+) exchanger-1 (NHE1) is a ubiquitous plasma membrane Na(+)/H(+) exchanger typically associated with maintenance of intracellular volume and pH. In addition to the NHE1 role in electroneutral Na(+)/H(+) transport, in renal tubular epithelial cells in vitro the polybasic, juxtamembrane NHE1 cytosolic tail domain acts as a scaffold, by binding with ezrin/radixin/moesin (ERM) proteins and phosphatidylinositol 4,5-bisphosphate, which initiates formation of a signaling complex that culminates in Akt activation and opposition to initial apoptotic stress. With robust apoptotic stimuli renal tubular epithelial cell NHE1 is a caspase substrate, and proteolytic cleavage may permit progression to apoptotic cell death. In vivo, genetic or pharmacological NHE1 loss of function causes renal tubule epithelial cell apoptosis and renal dysfunction following streptozotocin-induced diabetes, ureteral obstruction, and adriamycin-induced podocyte toxicity. Taken together, substantial in vivo and in vitro data demonstrate that NHE1 regulates tubular epithelial cell survival. In contrast to connotations of NHE1 as an unimportant "housekeeping" protein, this review highlights that NHE1 activity is critical for countering tubular atrophy and chronic renal disease progression.

  12. MicroRNA Regulation of Human Breast Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Yohei Shimono

    2015-12-01

    Full Text Available MicroRNAs (miRNAs are involved in virtually all biological processes, including stem cell maintenance, differentiation, and development. The dysregulation of miRNAs is associated with many human diseases including cancer. We have identified a set of miRNAs differentially expressed between human breast cancer stem cells (CSCs and non-tumorigenic cancer cells. In addition, these miRNAs are similarly upregulated or downregulated in normal mammary stem/progenitor cells. In this review, we mainly describe the miRNAs that are dysregulated in human breast CSCs directly isolated from clinical specimens. The miRNAs and their clusters, such as the miR-200 clusters, miR-183 cluster, miR-221-222 cluster, let-7, miR-142 and miR-214, target the genes and pathways important for stem cell maintenance, such as the self-renewal gene BMI1, apoptosis, Wnt signaling, Notch signaling, and epithelial-to-mesenchymal transition. In addition, the current evidence shows that metastatic breast CSCs acquire a phenotype that is different from the CSCs in a primary site. Thus, clarifying the miRNA regulation of the metastatic breast CSCs will further advance our understanding of the roles of human breast CSCs in tumor progression.

  13. Regulation of cell division in higher plants. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Thomas W.

    2000-02-29

    Research in the latter part of the grant period was divided into two parts: (1) expansion of the macromolecular tool kit for studying plant cell division; (2) experiments in which the roles played by plant cell cycle regulators were to be cast in the light of the emerging yeast and animal cell paradigm for molecular control of the mitotic cycle. The first objectives were accomplished to a very satisfactory degree. With regard to the second part of the project, we were driven to change our objectives for two reasons. First, the families of cell cycle control genes that we cloned encoded such closely related members that the prospects for success at raising distinguishing antisera against each were sufficiently dubious as to be impractical. Epitope tagging is not feasible in Pisum sativum, our experimental system, as this species is not realistically transformable. Therefore, differentiating the roles of diverse cyclins and cyclin-dependent kinases was problematic. Secondly, our procedure for generating mitotically synchronized pea root meristems for biochemical studies was far too labor intensive for the proposed experiments. We therefore shifted our objectives to identifying connections between the conserved proteins of the cell cycle engine and factors that interface it with plant physiology and development. In this, we have obtained some very exciting results.

  14. Endothelial cells regulate neural crest and second heart field morphogenesis

    Directory of Open Access Journals (Sweden)

    Michal Milgrom-Hoffman

    2014-07-01

    Full Text Available Cardiac and craniofacial developmental programs are intricately linked during early embryogenesis, which is also reflected by a high frequency of birth defects affecting both regions. The molecular nature of the crosstalk between mesoderm and neural crest progenitors and the involvement of endothelial cells within the cardio–craniofacial field are largely unclear. Here we show in the mouse that genetic ablation of vascular endothelial growth factor receptor 2 (Flk1 in the mesoderm results in early embryonic lethality, severe deformation of the cardio–craniofacial field, lack of endothelial cells and a poorly formed vascular system. We provide evidence that endothelial cells are required for migration and survival of cranial neural crest cells and consequently for the deployment of second heart field progenitors into the cardiac outflow tract. Insights into the molecular mechanisms reveal marked reduction in Transforming growth factor beta 1 (Tgfb1 along with changes in the extracellular matrix (ECM composition. Our collective findings in both mouse and avian models suggest that endothelial cells coordinate cardio–craniofacial morphogenesis, in part via a conserved signaling circuit regulating ECM remodeling by Tgfb1.

  15. Evolution of the CNS myelin gene regulatory program.

    Science.gov (United States)

    Li, Huiliang; Richardson, William D

    2016-06-15

    Myelin is a specialized subcellular structure that evolved uniquely in vertebrates. A myelinated axon conducts action potentials many times faster than an unmyelinated axon of the same diameter; for the same conduction speed, the unmyelinated axon would need a much larger diameter and volume than its myelinated counterpart. Hence myelin speeds information transfer and saves space, allowing the evolution of a powerful yet portable brain. Myelination in the central nervous system (CNS) is controlled by a gene regulatory program that features a number of master transcriptional regulators including Olig1, Olig2 and Myrf. Olig family genes evolved from a single ancestral gene in non-chordates. Olig2, which executes multiple functions with regard to oligodendrocyte identity and development in vertebrates, might have evolved functional versatility through post-translational modification, especially phosphorylation, as illustrated by its evolutionarily conserved serine/threonine phospho-acceptor sites and its accumulation of serine residues during more recent stages of vertebrate evolution. Olig1, derived from a duplicated copy of Olig2 in early bony fish, is involved in oligodendrocyte development and is critical to remyelination in bony vertebrates, but is lost in birds. The origin of Myrf orthologs might be the result of DNA integration between an invading phage or bacterium and an early protist, producing a fusion protein capable of self-cleavage and DNA binding. Myrf seems to have adopted new functions in early vertebrates - initiation of the CNS myelination program as well as the maintenance of mature oligodendrocyte identity and myelin structure - by developing new ways to interact with DNA motifs specific to myelin genes. This article is part of a Special Issue entitled SI: Myelin Evolution. PMID:26474911

  16. Evolution of the CNS myelin gene regulatory program.

    Science.gov (United States)

    Li, Huiliang; Richardson, William D

    2016-06-15

    Myelin is a specialized subcellular structure that evolved uniquely in vertebrates. A myelinated axon conducts action potentials many times faster than an unmyelinated axon of the same diameter; for the same conduction speed, the unmyelinated axon would need a much larger diameter and volume than its myelinated counterpart. Hence myelin speeds information transfer and saves space, allowing the evolution of a powerful yet portable brain. Myelination in the central nervous system (CNS) is controlled by a gene regulatory program that features a number of master transcriptional regulators including Olig1, Olig2 and Myrf. Olig family genes evolved from a single ancestral gene in non-chordates. Olig2, which executes multiple functions with regard to oligodendrocyte identity and development in vertebrates, might have evolved functional versatility through post-translational modification, especially phosphorylation, as illustrated by its evolutionarily conserved serine/threonine phospho-acceptor sites and its accumulation of serine residues during more recent stages of vertebrate evolution. Olig1, derived from a duplicated copy of Olig2 in early bony fish, is involved in oligodendrocyte development and is critical to remyelination in bony vertebrates, but is lost in birds. The origin of Myrf orthologs might be the result of DNA integration between an invading phage or bacterium and an early protist, producing a fusion protein capable of self-cleavage and DNA binding. Myrf seems to have adopted new functions in early vertebrates - initiation of the CNS myelination program as well as the maintenance of mature oligodendrocyte identity and myelin structure - by developing new ways to interact with DNA motifs specific to myelin genes. This article is part of a Special Issue entitled SI: Myelin Evolution.

  17. Differential expression of Toll-like receptor (TLR) and B cell receptor (BCR) signaling molecules in primary diffuse large B-cell lymphoma of the central nervous system.

    Science.gov (United States)

    Akhter, Ariz; Masir, Noraidah; Elyamany, Ghaleb; Phang, Kean-Chang; Mahe, Etienne; Al-Zahrani, Ali Matar; Shabani-Rad, Meer-Taher; Stewart, Douglas Allan; Mansoor, Adnan

    2015-01-01

    Primary diffuse large B-cell lymphoma of the central nervous system (CNS DLBCL) is a distinct and aggressive lymphoma that is confined to CNS. Since, central nervous system is barrier-protected and immunologically silent; role of TLR/BCR signaling in pathogenesis and biology of CNS DLBCL is intriguing. Genomic mutations in key regulators of TLR/BCR signaling pathway (MYD88/CD79B/CARD11) have recently been reported in this disease. These observations raised possible implications in novel targeted therapies; however, expression pattern of molecules related to TLR/BCR pathways in this lymphoma remains unknown. We have analyzed the expression of 19 genes encoding TLR/BCR pathways and targets in CNS DLBCLs (n = 20) by Nanostring nCounter™ analysis and compared it with expression patterns in purified reactive B-lymphocytes and systemic diffuse large B cell lymphoma (DLBCL) (n = 20). Relative expression of TLR4, TLR5, TLR9, CD79B and BLNK was higher in CNS DLBCLs than in control B-lymphocytes; where as TLR7, MALT1, BCL10, CD79A and LYN was lower in CNS DLBCLs (P 1.5 fold change; P < 0.01). The B cell receptor molecules like BLNK and CD79B were also associated with higher expression of MYD88 dependent TLRs (TLR4/5/9). In conclusion, we have shown over expression of TLR/BCR related genes or their targets, where genomic mutations have commonly been identified in CNS DLBCL. We have also demonstrated that TLR over expression closely relate with up regulation of genes associated with BCR pathway like CD79B/BLNK and CARD11, which play an important role in NF-kB pathway activation. Our results provide an important insight into the possibility of TLR and/or B-cell receptor signaling molecules as possible therapeutic targets in CNS DLBCL. PMID:25391967

  18. FAT10, a gene up-regulated in various cancers, is cell-cycle regulated

    OpenAIRE

    Zhang Dongwei; Lim Chuan-Bian; Lee Caroline GL

    2006-01-01

    Abstract Background FAT10 is a member of the ubiquitin-like-modifier family of proteins. Over-expression of the FAT10 gene was observed in the tumors of several epithelial cancers. High FAT10 expression was found to lead to increased chromosome instability via the reduction in the kinetochore localization of MAD2 during the prometaphase stage of the cell-cycle. FAT10 expression was also previously reported to be regulated by cytokines and p53. Results Here, we report that FAT10 expression is ...

  19. Mast Cell-activated Bone Marrow Mesenchymal Stromal Cells Regulate Proliferation and Lineage Commitment of CD34+ Progenitor cells

    Directory of Open Access Journals (Sweden)

    Zoulfia eAllakhverdi

    2013-12-01

    Full Text Available Background: Shortly after allergen exposure, the number of bone marrow and circulating CD34+ progenitors increases. We aim to analyze the possible mechanism whereby the allergic reaction stimulates bone marrow to release these effector cells in increased numbers. We hypothesize that mast cells may play a predominant role in this process. Objective: To examine the effect of IgE-activated mast cells on bone marrow mesenchymal stromal cells which regulate proliferation and differentiation of CD34+ progenitors. Methods: Primary mast cells were derived from CD34+ precursors and activated with IgE/anti-IgE. Bone marrow mesenchymal stromal cells were co-cultured with CD34+ progenitor cells and stimulated with IL1/TNF or IgE/anti-IgE activated mast cells in Transwell system. Results: Bone marrow mesenchymal stromal cells produce low level of TSLP under steady state conditions, which is markedly increased by stimulation with proinflammatory cytokines IL-1 and TNF or IgE-activated mast cells. The latter also triggers BM-MSCs production of G-CSF, and GM-CSF while inhibiting SDF-1. Mast cell-activated mesenchymal stromal cells stimulate CD34+ cells to proliferate and to regulate their expression of early allergy-associated genes. Conclusion and Clinical Relevance: This in vitro study indicates that IgE-activated mast cells trigger bone marrow mesenchymal stromal cells to release TSLP and hematopoietic growth factors and to regulate the proliferation and lineage commitment of CD34+ precursor cells. The data predict that the effective inhibition of mast cells should impair mobilization and accumulation of allergic effector cells and thereby reduce the severity of allergic diseases.

  20. Navigating the transcriptional roadmap regulating plant secondary cell wall deposition

    Directory of Open Access Journals (Sweden)

    Steven Grant Hussey

    2013-08-01

    Full Text Available The current status of lignocellulosic biomass as an invaluable resource in industry, agriculture and health has spurred increased interest in understanding the transcriptional regulation of secondary cell wall (SCW biosynthesis. The last decade of research has revealed an extensive network of NAC, MYB and other families of transcription factors regulating Arabidopsis SCW biosynthesis, and numerous studies have explored SCW-related transcription factors in other dicots and monocots. Whilst the general structure of the Arabidopsis network has been a topic of several reviews, they have not comprehensively represented the detailed protein-DNA and protein-protein interactions described in the literature, and an understanding of network dynamics and functionality has not yet been achieved for SCW formation. Furthermore the methodologies employed in studies of SCW transcriptional regulation have not received much attention, especially in the case of non-model organisms. In this review, we have reconstructed the most exhaustive literature-based network representations to date of SCW transcriptional regulation in Arabidopsis. We include a manipulable Cytoscape representation of the Arabidopsis SCW transcriptional network to aid in future studies, along with a list of supporting literature for each documented interaction. Amongst other topics, we discuss the various components of the network, its evolutionary conservation in plants, putative modules and dynamic mechanisms that may influence network function, and the approaches that have been employed in network inference. Future research should aim to better understand network function and its response to dynamic perturbations, whilst the development and application of genome-wide approaches such as ChIP-seq and systems genetics are in progress for the study of SCW transcriptional regulation in non-model organisms.

  1. Swelling-activated ion channels: functional regulation in cell-swelling, proliferation and apoptosis

    DEFF Research Database (Denmark)

    Stutzin, A; Hoffmann, E K

    2006-01-01

    Cell volume regulation is one of the most fundamental homeostatic mechanisms and essential for normal cellular function. At the same time, however, many physiological mechanisms are associated with regulatory changes in cell size meaning that the set point for cell volume regulation is under phys...... as key players in the maintenance of normal steady-state cell volume, with particular emphasis on the intracellular signalling pathways responsible for their regulation during hypotonic stress, cell proliferation and apoptosis....

  2. Regulation of plant cells, cell walls and development by mechanical signals

    Energy Technology Data Exchange (ETDEWEB)

    Meyerowitz, Elliot M. [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2016-06-14

    The overall goal of the revised scope of work for the final year of funding was to characterize cell wall biosynthesis in developing cotyledons and in the shoot apical meristem of Arabidopsis thaliana, as a way of learning about developmental control of cell wall biosynthesis in plants, and interactions between cell wall biosynthesis and the microtubule cytoskeleton. The proposed work had two parts – to look at the effect of mutation in the SPIRAL2 gene on microtubule organization and reorganization, and to thoroughly characterize the glycosyltransferase genes expressed in shoot apical meristems by RNA-seq experiments, by in situ hybridization of the RNAs expressed in the meristem, and by antibody staining of the products of the glycosyltransferases in meristems. Both parts were completed; the spiral2 mutant was found to speed microtubule reorientation after ablation of adjacent cells, supporting our hypothesis that reorganization correlates with microtubule severing, the rate of which is increased by the mutation. The glycosyltransferase characterization was completed and published as Yang et al. (2016). Among the new things learned was that primary cell wall biosynthesis is strongly controlled both by cell type, and by stage of cell cycle, implying not only that different, even adjacent, cells can have different sugar linkages in their (nonshared) walls, but also that a surprisingly large proportion of glycosyltransferases is regulated in the cell cycle, and therefore that the cell cycle regulates wall maturation to a degree previously unrecognized.

  3. REGULATION OF PLANT CELLS, CELL WALLS AND DEVELOPMENT BY MECHANICAL SIGNALS

    Energy Technology Data Exchange (ETDEWEB)

    Meyerowitz, Elliot M [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2016-08-22

    The overall goal of the revised scope of work for the final year of funding was to characterize cell wall biosynthesis in developing cotyledons and in the shoot apical meristem of Arabidopsis thaliana, as a way of learning about developmental control of cell wall biosynthesis in plants, and interactions between cell wall biosynthesis and the microtubule cytoskeleton. The proposed work had two parts – to look at the effect of mutation in the SPIRAL2 gene on microtubule organization and reorganization, and to thoroughly characterize the glycosyltransferase genes expressed in shoot apical meristems by RNA-seq experiments, by in situ hybridization of the RNAs expressed in the meristem, and by antibody staining of the products of the glycosyltransferases in meristems. Both parts were completed; the spiral2 mutant was found to speed microtubule reorientation after ablation of adjacent cells, supporting our hypothesis that reorganization correlates with microtubule severing, the rate of which is increased by the mutation. The glycosyltransferase characterization was completed and published as Yang et al. (2016). Among the new things learned was that primary cell wall biosynthesis is strongly controlled both by cell type, and by stage of cell cycle, implying not only that different, even adjacent, cells can have different sugar linkages in their (nonshared) walls, but also that a surprisingly large proportion of glycosyltransferases is regulated in the cell cycle, and therefore that the cell cycle regulates wall maturation to a degree previously unrecognized.

  4. Changes of the cell cycle regulators and cell cycle arrest in cervical cancer cells after cisplatin therapy

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective To investigate the changes of the cell cycle regulators ATM,Chk2 and p53 and cell cycle arrest in HeLa cells after cisplatin therapy. Methods The proliferation-inhibiting rates of HeLa cells induced by cisplatin of different concentrations were measured by MTT assays. The mRNA and protein expressions of ATM,Chk2 and p53 of HeLa cells with and without cisplatin were detected by RT-PCR and Western blot,respectively. The cell cycle analysis was conducted by flow cytometric analysis. Results Cisplatin...

  5. RAGE regulates immune cell infiltration and angiogenesis in choroidal neovascularization.

    Directory of Open Access Journals (Sweden)

    Mei Chen

    Full Text Available PURPOSE: RAGE regulates pro-inflammatory responses in diverse cells and tissues. This study has investigated if RAGE plays a role in immune cell mobilization and choroidal neovascular pathology that is associated with the neovascular form of age-related macular degeneration (nvAMD. METHODS: RAGE null (RAGE-/- mice and age-matched wild type (WT control mice underwent laser photocoagulation to generate choroidal neovascularization (CNV lesions which were then analyzed for morphology, S100B immunoreactivity and inflammatory cell infiltration. The chemotactic ability of bone marrow derived macrophages (BMDMs towards S100B was investigated. RESULTS: RAGE expression was significantly increased in the retina during CNV of WT mice (p<0.001. RAGE-/- mice exhibited significantly reduced CNV lesion size when compared to WT controls (p<0.05. S100B mRNA was upregulated in the lasered WT retina but not RAGE-/- retina and S100B immunoreactivity was present within CNV lesions although levels were less when RAGE-/- mice were compared to WT controls. Activated microglia in lesions were considerably less abundant in RAGE-/- mice when compared to WT counterparts (p<0.001. A dose dependent chemotactic migration was observed in BMDMs from WT mice (p<0.05-0.01 but this was not apparent in cells isolated from RAGE-/- mice. CONCLUSIONS: RAGE-S100B interactions appear to play an important role in CNV lesion formation by regulating pro-inflammatory and angiogenic responses. This study highlights the role of RAGE in inflammation-mediated outer retinal pathology.

  6. Nanomaterials for regulating cancer and stem cell fate

    Science.gov (United States)

    Shah, Birju P.

    The realm of nanomedicine has grown exponentially over the past few decades. However, there are several obstacles that need to be overcome, prior to the wide-spread clinical applications of these nanoparticles, such as (i) developing well-defined nanoparticles of varying size, morphology and composition to enable various clinical applications; (ii) overcome various physiological barriers encountered in order to deliver the therapeutics to the target location; and (iii) real-time monitoring of the nano-therapeutics within the human body for tracking their uptake, localization and effect. Hence, this dissertation focuses on developing multimodal nanotechnology-based approaches to overcome the above-mentioned challenges and thus enable regulation of cancer and stem cell fate. The initial part of this dissertation describes the development of multimodal magnetic core-shell nanoparticles (MCNPs), comprised of a highly magnetic core surrounded by a thin gold shell, thus combining magnetic and plasmonic properties. These nanoparticles were utilized for mainly two applications: (i) Magnetically-facilitated delivery of siRNA and plasmid DNA for effective stem cell differentiation and imaging and (ii) Combined hyperthermia and targeted delivery of a mitochondria-targeting peptide for enhancing apoptosis in cancer cells. The following part of this dissertation presents the generation of a multi-functional cyclodextrin-conjugated polymeric delivery platform (known as DexAMs), for co-delivery of anticancer drugs and siRNAs in a target-specific manner to brain tumor cells. This combined delivery of chemotherapeutics and siRNA resulted in a synergistic effect on the apoptosis of brain tumor cells, as compared to the individual treatments. The final part of this thesis presents development of stimuli-responsive uorescence resonance energy transfer (FRET)-based mesoporous silica nanoparticles for real-time monitoring of drug release in cells. The stimuli-responsive behavior of

  7. Spiking and non-spiking classes of oligodendrocyte precursor glia in CNS white matter

    OpenAIRE

    Káradóttir, Ragnhildur; Hamilton, Nicola B.; Bakiri, Yamina; Attwell, David

    2008-01-01

    A defining feature of glial cells has been their inability to generate action potentials. We now show that there are two distinct types of morphologically identical oligodendrocyte precursor glial cell (OPC) in situ in rat CNS white matter. One type expresses voltage-gated sodium and potassium channels, generates action potentials when depolarized, and senses its environment by receiving excitatory and inhibitory synaptic input from axons. The other type lacks action potentials and synaptic i...

  8. Serum exosomes in pregnancy-associated immune modulation and neuroprotection during CNS autoimmunity

    OpenAIRE

    Williams, Jessica L.; Gatson, NaTosha N.; Smith, Kristen M; Almad, Akshata; McTigue, Dana M; Whitacre, Caroline C

    2013-01-01

    In multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), relapses are markedly reduced during pregnancy. Exosomes are lipid-bound vesicles and are more abundant in the serum during pregnancy. We demonstrate that serum exosomes suppress T cell activation, promote the maturation of oligodendrocyte precursor cells (OPC), and pregnancy exosomes facilitate OPC migration into active CNS lesions. However, exosomes derived from both pregnant and non-pregnant mice reduced the se...

  9. Folate receptor {alpha} regulates cell proliferation in mouse gonadotroph {alpha}T3-1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Congjun; Evans, Chheng-Orn [Department of Neurosurgery and Laboratory of Molecular Neurosurgery and Biotechnology, Emory University, School of Medicine, Atlanta, Georgia (United States); Stevens, Victoria L. [Epidemiology and Surveillance Research, American Cancer Society, Atlanta, Georgia (United States); Owens, Timothy R. [Emory University, School of Medicine, Atlanta, Georgia (United States); Oyesiku, Nelson M., E-mail: noyesik@emory.edu [Department of Neurosurgery and Laboratory of Molecular Neurosurgery and Biotechnology, Emory University, School of Medicine, Atlanta, Georgia (United States)

    2009-11-01

    We have previously found that the mRNA and protein levels of the folate receptor alpha (FR{alpha}) are uniquely over-expressed in clinically human nonfunctional (NF) pituitary adenomas, but the mechanistic role of FR{alpha} has not fully been determined. We investigated the effect of FR{alpha} over-expression in the mouse gonadotroph {alpha}T3-1 cell line as a model for NF pituitary adenomas. We found that the expression and function of FR{alpha} were strongly up-regulated, by Western blotting and folic acid binding assay. Furthermore, we found a higher cell growth rate, an enhanced percentage of cells in S-phase by BrdU assay, and a higher PCNA staining. These observations indicate that over-expression of FR{alpha} promotes cell proliferation. These effects were abrogated in the same {alpha}T3-1 cells when transfected with a mutant FR{alpha} cDNA that confers a dominant-negative phenotype by inhibiting folic acid binding. Finally, by real-time quantitative PCR, we found that mRNA expression of NOTCH3 was up-regulated in FR{alpha} over-expressing cells. In summary, our data suggests that FR{alpha} regulates pituitary tumor cell proliferation and mechanistically may involve the NOTCH pathway. Potentially, this finding could be exploited to develop new, innovative molecular targeted treatment for human NF pituitary adenomas.

  10. Folate receptor α regulates cell proliferation in mouse gonadotroph αT3-1 cells

    International Nuclear Information System (INIS)

    We have previously found that the mRNA and protein levels of the folate receptor alpha (FRα) are uniquely over-expressed in clinically human nonfunctional (NF) pituitary adenomas, but the mechanistic role of FRα has not fully been determined. We investigated the effect of FRα over-expression in the mouse gonadotroph αT3-1 cell line as a model for NF pituitary adenomas. We found that the expression and function of FRα were strongly up-regulated, by Western blotting and folic acid binding assay. Furthermore, we found a higher cell growth rate, an enhanced percentage of cells in S-phase by BrdU assay, and a higher PCNA staining. These observations indicate that over-expression of FRα promotes cell proliferation. These effects were abrogated in the same αT3-1 cells when transfected with a mutant FRα cDNA that confers a dominant-negative phenotype by inhibiting folic acid binding. Finally, by real-time quantitative PCR, we found that mRNA expression of NOTCH3 was up-regulated in FRα over-expressing cells. In summary, our data suggests that FRα regulates pituitary tumor cell proliferation and mechanistically may involve the NOTCH pathway. Potentially, this finding could be exploited to develop new, innovative molecular targeted treatment for human NF pituitary adenomas.

  11. Ventriculomegaly with non-CNS anomalies

    International Nuclear Information System (INIS)

    We correlated fetal magnetic resonance (MR) imaging findings with postnatal clinical findings to assess ventriculomegaly with non-CNS anomalies. From 2002 to 2010, 52 fetuses underwent a MRI for evaluation of ventriculomegaly after ultrasonography (US). Ten of the 52 demonstrated anomalies outside the central nervous system (CNS), including trisomy 8, trisomy 18, X-linked hydrocephalus, CHARGE/Potter sequences, VATER association, oral-facial-digital syndrome, esophageal atresia type C, or external auditory canal stenosis. Examinations were performed between 24 and 35 weeks' gestation. MR imaging was performed in a 1.5-tesla unit using a phased-array coil without preparation. Fetal MR imaging showed abnormalities of the kidney, bladder, duodenum, and thumbs but did not permit diagnosis of esophageal atresia type C or craniofacial, anorectal, or skeletal anomalies. Cardiac anomaly was most frequent, but fetal MR imaging did not allow final diagnosis of congenital heart disease. On both US and MR imaging, esophageal atresia type C and anorectal anomaly were undetected; normal rectal signal in a case of anorectal anomaly without urorectal fistula did not lead to suspicion of anomaly. Observation of adducted thumbs on MR imaging is an important sign of X-linked hydrocephalus. The slice area used in this study did not cover polydactyly, which accompanies oral-facial-digital syndrome. US and MR imaging are complementary imaging methods used to evaluate ventriculomegaly. Fetal MR imaging should cover the kidney, bladder, and fingers. Further work is needed to determine the anomalies that can be clearly detected by fetal MR imaging. (author)

  12. Calcium in ciliated protozoa: sources, regulation, and calcium-regulated cell functions.

    Science.gov (United States)

    Plattner, H; Klauke, N

    2001-01-01

    In ciliates, a variety of processes are regulated by Ca2+, e.g., exocytosis, endocytosis, ciliary beat, cell contraction, and nuclear migration. Differential microdomain regulation may occur by activation of specific channels in different cell regions (e.g., voltage-dependent Ca2+ channels in cilia), by local, nonpropagated activation of subplasmalemmal Ca stores (alveolar sacs), by different sensitivity thresholds, and eventually by interplay with additional second messengers (cilia). During stimulus-secretion coupling, Ca2+ as the only known second messenger operates at approximately 5 microM, whereby mobilization from alveolar sacs is superimposed by "store-operated Ca2+ influx" (SOC), to drive exocytotic and endocytotic membrane fusion. (Content discharge requires binding of extracellular Ca2+ to some secretory proteins.) Ca2+ homeostasis is reestablished by binding to cytosolic Ca2+-binding proteins (e.g., calmodulin), by sequestration into mitochondria (perhaps by Ca2+ uniporter) and into endoplasmic reticulum and alveolar sacs (with a SERCA-type pump), and by extrusion via a plasmalemmal Ca2+ pump and a Na+/Ca2+ exchanger. Comparison of free vs total concentration, [Ca2+] vs [Ca], during activation, using time-resolved fluorochrome analysis and X-ray microanalysis, respectively, reveals that altogether activation requires a calcium flux that is orders of magnitude larger than that expected from the [Ca2+] actually required for local activation.

  13. Regulation of CREB by moderate hypoxia in PC12 cells.

    Science.gov (United States)

    Beitner-Johnson, D; Rust, R T; Hsieh, T; Millhorn, D E

    2000-01-01

    The mechanisms by which excitable cells adapt and respond to changes in O2 levels remain largely unknown. We have investigated the effect of hypoxia on the cyclic AMP response element binding protein (CREB) transcription factor. PC12 cells were exposed to moderate levels of hypoxia (5% O2) for various times between 20 min and 6 hr. We found that hypoxia rapidly and persistently induced ser133 phosphorylation of CREB. This effect was more robust than that produced by exposing PC12 cells to either forskolin, KCl, or NGF. This effect was not due to activation of any of the previously known CREB kinases, including PKA, CaMK, PKC, p70s6k, or MAPKAP kinase-2. Thus, hypoxia may induce activation of a novel CREB kinase. To test whether phosphorylation of CREB was associated with an activation of CRE-dependent gene expression, cells were transfected with wild type and mutated regions of the 5'-flanking region of the tyrosine hydroxylase (TH) gene fused to a CAT reporter gene. Mutation of the CRE element in a TH reporter gene reduced, but did not abolish, the effects of hypoxia on TH gene expression. However, hypoxia did not induce transactivation of a GAL4-luciferase reporter by a GAL4-CREB fusion protein. Thus, the mechanism by which hypoxia regulates CREB is distinct, and more complex, than that induced by forskolin, depolarization, or nerve growth factor. PMID:10849656

  14. Bioelectrical Regulation of Cell Cycle and the Planarian Model System

    Science.gov (United States)

    Barghouth, Paul G.; Thiruvalluvan, Manish; Oviedo, Néstor J.

    2015-01-01

    Cell cycle regulation through the manipulation of endogenous membrane potentials offers tremendous opportunities to control cellular processes during tissue repair and cancer formation. However, the molecular mechanisms by which biophysical signals modulate the cell cycle remain underappreciated and poorly understood. Cells in complex organisms generate and maintain a constant voltage gradient across the plasma membrane known as the transmembrane potential. This potential, generated through the combined efforts of various ion transporters, pumps and channels, is known to drive a wide range of cellular processes such as cellular proliferation, migration and tissue regeneration while its deregulation can lead to tumorigenesis. These cellular regulatory events, coordinated by ionic flow, correspond to a new and exciting field termed molecular bioelectricity. We aim to present a brief discussion on the biophysical machinery involving membrane potential and the mechanisms mediating cell cycle progression and cancer transformation. Furthermore, we present the planarian Schmidtea mediterranea as a tractable model system for understanding principles behind molecular bioelectricity at both the cellular and organismal level. PMID:25749155

  15. Transcriptional regulation of cathelicidin genes in chicken bone marrow cells.

    Science.gov (United States)

    Lee, Sang In; Jang, Hyun June; Jeon, Mi-hyang; Lee, Mi Ock; Kim, Jeom Sun; Jeon, Ik-Soo; Byun, Sung June

    2016-04-01

    Cathelicidins form a family of vertebrate-specific immune molecules with an evolutionarily conserved gene structure. We analyzed the expression patterns of cathelicidin genes (CAMP, CATH3, and CATHB1) in chicken bone marrow cells (BMCs) and chicken embryonic fibroblasts (CEFs). We found that CAMP and CATHB1 were significantly up-regulated in BMCs, whereas the expression of CATH3 did not differ significantly between BMCs and CEFs. To study the mechanism underlying the up-regulation of cathelicidin genes in BMCs, we predicted the transcription factors (TFs) that bind to the 5'-flanking regions of cathelicidin genes. CEBPA, EBF1, HES1, MSX1, and ZIC3 were up-regulated in BMCs compared to CEFs. Subsequently, when a siRNA-mediated knockdown assay was performed for MSX1, the expression of CAMP and CATHB1 was decreased in BMCs. We also showed that the transcriptional activity of the CAMP promoter was decreased by mutation of the MSX1-binding sites present within the 5'-flanking region of CAMP. These results increase our understanding of the regulatory mechanisms controlling cathelicidin genes in BMCs.

  16. Cocaine- and amphetamine-regulated transcript (CART) protects beta cells against glucotoxicity and increases cell proliferation.

    Science.gov (United States)

    Sathanoori, Ramasri; Olde, Björn; Erlinge, David; Göransson, Olga; Wierup, Nils

    2013-02-01

    Cocaine- and amphetamine-regulated transcript (CART) is an islet peptide that promotes glucose-stimulated insulin secretion in beta cells via cAMP/PKA-dependent pathways. In addition, CART is a regulator of neuronal survival. In this study, we examined the effect of exogenous CART 55-102 on beta cell viability and dissected its signaling mechanisms. Evaluation of DNA fragmentation and chromatin condensation revealed that CART 55-102 reduced glucotoxicity-induced apoptosis in both INS-1 (832/13) cells and isolated rat islets. Glucotoxicity in INS-1 (832/13) cells also caused a 50% reduction of endogenous CART protein. We show that CART increased proliferation in INS-1 (832/13) cells, an effect that was blocked by PKA, PKB, and MEK1 inhibitors. In addition, CART induced phosphorylation of CREB, IRS, PKB, FoxO1, p44/42 MAPK, and p90RSK in INS-1 (832/13) cells and isolated rat islets, all key mediators of cell survival and proliferation. Thus, we demonstrate that CART 55-102 protects beta cells against glucotoxicity and promotes proliferation. Taken together our data point to the potential use of CART in therapeutic interventions targeted at enhancing functional beta cell mass and long-term insulin secretion in T2D. PMID:23250745

  17. Vesicle Size Regulates Nanotube Formation in the Cell

    Science.gov (United States)

    Su, Qian Peter; Du, Wanqing; Ji, Qinghua; Xue, Boxin; Jiang, Dong; Zhu, Yueyao; Lou, Jizhong; Yu, Li; Sun, Yujie

    2016-01-01

    Intracellular membrane nanotube formation and its dynamics play important roles for cargo transportation and organelle biogenesis. Regarding the regulation mechanisms, while much attention has been paid on the lipid composition and its associated protein molecules, effects of the vesicle size has not been studied in the cell. Giant unilamellar vesicles (GUVs) are often used for in vitro membrane deformation studies, but they are much larger than most intracellular vesicles and the in vitro studies also lack physiological relevance. Here, we use lysosomes and autolysosomes, whose sizes range between 100 nm and 1 μm, as model systems to study the size effects on nanotube formation both in vivo and in vitro. Single molecule observations indicate that driven by kinesin motors, small vesicles (100–200 nm) are mainly transported along the tracks while a remarkable portion of large vesicles (500–1000 nm) form nanotubes. This size effect is further confirmed by in vitro reconstitution assays on liposomes and purified lysosomes and autolysosomes. We also apply Atomic Force Microscopy (AFM) to measure the initiation force for nanotube formation. These results suggest that the size-dependence may be one of the mechanisms for cells to regulate cellular processes involving membrane-deformation, such as the timing of tubulation-mediated vesicle recycling. PMID:27052881

  18. Vesicle Size Regulates Nanotube Formation in the Cell.

    Science.gov (United States)

    Su, Qian Peter; Du, Wanqing; Ji, Qinghua; Xue, Boxin; Jiang, Dong; Zhu, Yueyao; Lou, Jizhong; Yu, Li; Sun, Yujie

    2016-04-07

    Intracellular membrane nanotube formation and its dynamics play important roles for cargo transportation and organelle biogenesis. Regarding the regulation mechanisms, while much attention has been paid on the lipid composition and its associated protein molecules, effects of the vesicle size has not been studied in the cell. Giant unilamellar vesicles (GUVs) are often used for in vitro membrane deformation studies, but they are much larger than most intracellular vesicles and the in vitro studies also lack physiological relevance. Here, we use lysosomes and autolysosomes, whose sizes range between 100 nm and 1 μm, as model systems to study the size effects on nanotube formation both in vivo and in vitro. Single molecule observations indicate that driven by kinesin motors, small vesicles (100-200 nm) are mainly transported along the tracks while a remarkable portion of large vesicles (500-1000 nm) form nanotubes. This size effect is further confirmed by in vitro reconstitution assays on liposomes and purified lysosomes and autolysosomes. We also apply Atomic Force Microscopy (AFM) to measure the initiation force for nanotube formation. These results suggest that the size-dependence may be one of the mechanisms for cells to regulate cellular processes involving membrane-deformation, such as the timing of tubulation-mediated vesicle recycling.

  19. Regulation of cell-to-cell variability in divergent gene expression

    Science.gov (United States)

    Yan, Chao; Wu, Shuyang; Pocetti, Christopher; Bai, Lu

    2016-03-01

    Cell-to-cell variability (noise) is an important feature of gene expression that impacts cell fitness and development. The regulatory mechanism of this variability is not fully understood. Here we investigate the effect on gene expression noise in divergent gene pairs (DGPs). We generated reporters driven by divergent promoters, rearranged their gene order, and probed their expressions using time-lapse fluorescence microscopy and single-molecule fluorescence in situ hybridization (smFISH). We show that two genes in a co-regulated DGP have higher expression covariance compared with the separate, tandem and convergent configurations, and this higher covariance is caused by more synchronized firing of the divergent transcriptions. For differentially regulated DGPs, the regulatory signal of one gene can stochastically `leak' to the other, causing increased gene expression noise. We propose that the DGPs' function in limiting or promoting gene expression noise may enhance or compromise cell fitness, providing an explanation for the conservation pattern of DGPs.

  20. Regulation of VH replacement by B cell receptor-mediated signaling in human immature B cells.

    Science.gov (United States)

    Liu, Jing; Lange, Miles D; Hong, Sang Yong; Xie, Wanqin; Xu, Kerui; Huang, Lin; Yu, Yangsheng; Ehrhardt, Götz R A; Zemlin, Michael; Burrows, Peter D; Su, Kaihong; Carter, Robert H; Zhang, Zhixin

    2013-06-01

    VH replacement provides a unique RAG-mediated recombination mechanism to edit nonfunctional IgH genes or IgH genes encoding self-reactive BCRs and contributes to the diversification of Ab repertoire in the mouse and human. Currently, it is not clear how VH replacement is regulated during early B lineage cell development. In this article, we show that cross-linking BCRs induces VH replacement in human EU12 μHC(+) cells and in the newly emigrated immature B cells purified from peripheral blood of healthy donors or tonsillar samples. BCR signaling-induced VH replacement is dependent on the activation of Syk and Src kinases but is inhibited by CD19 costimulation, presumably through activation of the PI3K pathway. These results show that VH replacement is regulated by BCR-mediated signaling in human immature B cells, which can be modulated by physiological and pharmacological treatments.

  1. Local positive feedback regulation determines cell shape in root hair cells.

    Science.gov (United States)

    Takeda, Seiji; Gapper, Catherine; Kaya, Hidetaka; Bell, Elizabeth; Kuchitsu, Kazuyuki; Dolan, Liam

    2008-02-29

    The specification and maintenance of growth sites are tightly regulated during cell morphogenesis in all organisms. ROOT HAIR DEFECTIVE 2 reduced nicotinamide adenine dinucleotide phosphate (RHD2 NADPH) oxidase-derived reactive oxygen species (ROS) stimulate a Ca2+ influx into the cytoplasm that is required for root hair growth in Arabidopsis thaliana. We found that Ca2+, in turn, activated the RHD2 NADPH oxidase to produce ROS at the growing point in the root hair. Together, these components could establish a means of positive feedback regulation that maintains an active growth site in expanding root hair cells. Because the location and stability of growth sites predict the ultimate form of a plant cell, our findings demonstrate how a positive feedback mechanism involving RHD2, ROS, and Ca2+ can determine cell shape.

  2. Towards Defining the Role of CNS Circuits in Control of Energy Homeostasis

    OpenAIRE

    Heß, Simon

    2011-01-01

    Healthy individuals are able to maintain a steady body weight over a long period of time due to an active process called energy homeostasis in which food intake is matched to energy expenditure with great precision. Once this tightly regulated system becomes unbalanced, weight gain and, on a longer time scale, obesity will develop. The control of energy homeostasis is accomplished by neuronal circuits within the CNS. These cir- cuits‚ are able to modulate food intake and energy expenditure in...

  3. Inflammatory cytokines in the brain: does the CNS shape immune responses?

    DEFF Research Database (Denmark)

    Owens, T; Renno, T; Taupin, V;

    1994-01-01

    Immune responses in the central nervous system (CNS) have traditionally been regarded as representing the intrusion of an unruly, ill-behaved mob of leukocytes into the well-ordered and organized domain of thought and reason. However, results accumulated over the past few years suggest that, far ...... may be subverted to autoimmunity, they suggest that the study of inflammatory autoimmune disease in the brain may shed light on the ability of the local environment to regulate immune responses....

  4. Regulation of sphingomyelin metabolism.

    Science.gov (United States)

    Bienias, Kamil; Fiedorowicz, Anna; Sadowska, Anna; Prokopiuk, Sławomir; Car, Halina

    2016-06-01

    Sphingolipids (SFs) represent a large class of lipids playing diverse functions in a vast number of physiological and pathological processes. Sphingomyelin (SM) is the most abundant SF in the cell, with ubiquitous distribution within mammalian tissues, and particularly high levels in the Central Nervous System (CNS). SM is an essential element of plasma membrane (PM) and its levels are crucial for the cell function. SM content in a cell is strictly regulated by the enzymes of SM metabolic pathways, which activities create a balance between SM synthesis and degradation. The de novo synthesis via SM synthases (SMSs) in the last step of the multi-stage process is the most important pathway of SM formation in a cell. The SM hydrolysis by sphingomyelinases (SMases) increases the concentration of ceramide (Cer), a bioactive molecule, which is involved in cellular proliferation, growth and apoptosis. By controlling the levels of SM and Cer, SMSs and SMases maintain cellular homeostasis. Enzymes of SM cycle exhibit unique properties and diverse tissue distribution. Disturbances in their activities were observed in many CNS pathologies. This review characterizes the physiological roles of SM and enzymes controlling SM levels as well as their involvement in selected pathologies of the Central Nervous System, such as ischemia/hypoxia, Alzheimer disease (AD), Parkinson disease (PD), depression, schizophrenia and Niemann Pick disease (NPD). PMID:26940196

  5. ZAP-70 kinase regulates HIV cell-to-cell spread and virological synapse formation

    OpenAIRE

    Sol-Foulon, Nathalie; Sourisseau, Marion; Porrot, Françoise; Thoulouze, Maria-Isabel; Trouillet, Céline; Nobile, Cinzia; Blanchet, Fabien; Di Bartolo, Vincenzo; Noraz, Nelly; Taylor, Naomi; Alcover, Andres; Hivroz, Claire; Schwartz, Olivier

    2007-01-01

    HIV efficiently spreads in lymphocytes, likely through virological synapses (VSs). These cell–cell junctions share some characteristics with immunological synapses, but cellular proteins required for their constitution remain poorly characterized. We have examined here the role of ZAP-70, a key kinase regulating T-cell activation and immunological synapse formation, in HIV replication. In lymphocytes deficient for ZAP-70, or expressing a kinase-dead mutant of the protein, HIV replication was ...

  6. Innate lymphoid cells regulate CD4+ T-cell responses to intestinal commensal bacteria.

    Science.gov (United States)

    Hepworth, Matthew R; Monticelli, Laurel A; Fung, Thomas C; Ziegler, Carly G K; Grunberg, Stephanie; Sinha, Rohini; Mantegazza, Adriana R; Ma, Hak-Ling; Crawford, Alison; Angelosanto, Jill M; Wherry, E John; Koni, Pandelakis A; Bushman, Frederic D; Elson, Charles O; Eberl, Gérard; Artis, David; Sonnenberg, Gregory F

    2013-06-01

    Innate lymphoid cells (ILCs) are a recently characterized family of immune cells that have critical roles in cytokine-mediated regulation of intestinal epithelial cell barrier integrity. Alterations in ILC responses are associated with multiple chronic human diseases, including inflammatory bowel disease, implicating a role for ILCs in disease pathogenesis. Owing to an inability to target ILCs selectively, experimental studies assessing ILC function have predominantly used mice lacking adaptive immune cells. However, in lymphocyte-sufficient hosts ILCs are vastly outnumbered by CD4(+) T cells, which express similar profiles of effector cytokines. Therefore, the function of ILCs in the presence of adaptive immunity and their potential to influence adaptive immune cell responses remain unknown. To test this, we used genetic or antibody-mediated depletion strategies to target murine ILCs in the presence of an adaptive immune system. We show that loss of retinoic-acid-receptor-related orphan receptor-γt-positive (RORγt(+)) ILCs was associated with dysregulated adaptive immune cell responses against commensal bacteria and low-grade systemic inflammation. Remarkably, ILC-mediated regulation of adaptive immune cells occurred independently of interleukin (IL)-17A, IL-22 or IL-23. Genome-wide transcriptional profiling and functional analyses revealed that RORγt(+) ILCs express major histocompatibility complex class II (MHCII) and can process and present antigen. However, rather than inducing T-cell proliferation, ILCs acted to limit commensal bacteria-specific CD4(+) T-cell responses. Consistent with this, selective deletion of MHCII in murine RORγt(+) ILCs resulted in dysregulated commensal bacteria-dependent CD4(+) T-cell responses that promoted spontaneous intestinal inflammation. These data identify that ILCs maintain intestinal homeostasis through MHCII-dependent interactions with CD4(+) T cells that limit pathological adaptive immune cell responses to commensal

  7. DICER Regulates the Formation and Maintenance of Cell-Cell Junctions in the Mouse Seminiferous Epithelium.

    Science.gov (United States)

    Korhonen, Hanna Maria; Yadav, Ram Prakash; Da Ros, Matteo; Chalmel, Frédéric; Zimmermann, Céline; Toppari, Jorma; Nef, Serge; Kotaja, Noora

    2015-12-01

    The endonuclease DICER that processes micro-RNAs and small interfering RNAs is essential for normal spermatogenesis and male fertility. We previously showed that the deletion of Dicer1 gene in postnatal spermatogonia in mice using Ngn3 promoter-driven Cre expression caused severe defects in the morphogenesis of haploid spermatid to mature spermatozoon, including problems in cell polarization and nuclear elongation. In this study, we further analyzed the same mouse model and revealed that absence of functional DICER in differentiating male germ cells induces disorganization of the cell-cell junctions in the seminiferous epithelium. We detected discontinuous and irregular apical ectoplasmic specializations between elongating spermatids and Sertoli cells. The defective anchoring of spermatids to Sertoli cells caused a premature release of spermatids into the lumen. Our findings may help also explain the abnormal elongation process of remaining spermatids because these junctions and the correct positioning of germ cells in the epithelium are critically important for the progression of spermiogenesis. Interestingly, cell adhesion-related genes were generally upregulated in Dicer1 knockout germ cells. Claudin 5 ( Cldn5 ) was among the most upregulated genes and we show that the polarized localization of CLAUDIN5 in the apical ectoplasmic specializations was lost in Dicer1 knockout spermatids. Our results suggest that DICER-dependent pathways control the formation and organization of cell-cell junctions in the seminiferous epithelium via the regulation of cell adhesion-related genes. PMID:26510868

  8. CNS Involvement in AML Patient Treated with 5-Azacytidine

    OpenAIRE

    Diamantina Vasilatou; Sotirios Papageorgiou; Efthymia Bazani; Athina Prasouli; Christina Economopoulou; Christoforos Roumpakis; Petros Karakitsos; George Dimitriadis; Vasiliki Pappa

    2014-01-01

    Central nervous system (CNS) involvement in acute myeloid leukemia (AML) is a rare complication of the disease and is associated with poor prognosis. Sometimes the clinical presentation can be unspecific and the diagnosis can be very challenging. Here we report a case of CNS infiltration in a patient suffering from AML who presented with normal complete blood count and altered mental status.

  9. CNS Involvement in AML Patient Treated with 5-Azacytidine.

    Science.gov (United States)

    Vasilatou, Diamantina; Papageorgiou, Sotirios; Bazani, Efthymia; Prasouli, Athina; Economopoulou, Christina; Roumpakis, Christoforos; Karakitsos, Petros; Dimitriadis, George; Pappa, Vasiliki

    2014-01-01

    Central nervous system (CNS) involvement in acute myeloid leukemia (AML) is a rare complication of the disease and is associated with poor prognosis. Sometimes the clinical presentation can be unspecific and the diagnosis can be very challenging. Here we report a case of CNS infiltration in a patient suffering from AML who presented with normal complete blood count and altered mental status. PMID:25197583

  10. CNS Involvement in AML Patient Treated with 5-Azacytidine

    Science.gov (United States)

    Vasilatou, Diamantina; Papageorgiou, Sotirios; Bazani, Efthymia; Prasouli, Athina; Economopoulou, Christina; Roumpakis, Christoforos; Karakitsos, Petros; Dimitriadis, George; Pappa, Vasiliki

    2014-01-01

    Central nervous system (CNS) involvement in acute myeloid leukemia (AML) is a rare complication of the disease and is associated with poor prognosis. Sometimes the clinical presentation can be unspecific and the diagnosis can be very challenging. Here we report a case of CNS infiltration in a patient suffering from AML who presented with normal complete blood count and altered mental status. PMID:25197583

  11. Heparan Sulfate Proteoglycans Regulate Fgf Signaling and Cell Polarity during Collective Cell Migration

    Directory of Open Access Journals (Sweden)

    Marina Venero Galanternik

    2015-01-01

    Full Text Available Collective cell migration is a highly regulated morphogenetic movement during embryonic development and cancer invasion that involves the precise orchestration and integration of cell-autonomous mechanisms and environmental signals. Coordinated lateral line primordium migration is controlled by the regulation of chemokine receptors via compartmentalized Wnt/β-catenin and fibroblast growth factor (Fgf signaling. Analysis of mutations in two exostosin glycosyltransferase genes (extl3 and ext2 revealed that loss of heparan sulfate (HS chains results in a failure of collective cell migration due to enhanced Fgf ligand diffusion and loss of Fgf signal transduction. Consequently, Wnt/β-catenin signaling is activated ectopically, resulting in the subsequent loss of the chemokine receptor cxcr7b. Disruption of HS proteoglycan (HSPG function induces extensive, random filopodia formation, demonstrating that HSPGs are involved in maintaining cell polarity in collectively migrating cells. The HSPGs themselves are regulated by the Wnt/β-catenin and Fgf pathways and thus are integral components of the regulatory network that coordinates collective cell migration with organ specification and morphogenesis.

  12. Neuritin is expressed in Schwann cells and down-regulated in apoptotic Schwann cells under hyperglycemia.

    Science.gov (United States)

    Min, Shi; Jian-bo, Li; Hong-man, Zhang; Ling-fei, Yan; Min, Xie; Jia-wei, Chen

    2012-11-01

    We aimed to explore neuritin expression in Schwann cells under different glucose conditions. Expression of neuritin at the levels of transcription and translation in purified Schwann cells was detected and measured using reverse transcriptase (RT) (quantitative) polymerase chain reaction (PCR) and western blot. Apoptosis of Schwann cells was measured by flow cytometry using Fluorescence Activated Cell Sorter (FACS) analysis and caspase fluorometric assay. Neuritin mRNA and protein were detected in cultured primary Schwann cells. Neuritin was identified as cell membrane form of protein and predominately as secreted or solube form of protein. Neuritin was significantly lower in 150 mM glucose condition, and more significantly lower in 300 mM glucose, than 5.6 mM glucose condition at 36 hours and especially at 48 hours of the culture, respectively (P Neuritin and apoptosis were correlated in a power regression (P neuritin mRNA and protein were expressed and down-regulated in Schwann cells under high-glucose concentration and the down-regulation may contribute to apopotosis of Schwann cells. PMID:22782233

  13. The orphan nuclear receptor Nr4a1 couples sympathetic and inflammatory cues in CNS-recruited macrophages to limit neuroinflammation

    Science.gov (United States)

    Shaked, Iftach; Hanna, Richard N.; Shaked, Helena; Chodaczek, Grzegorz; Nowyhed, Heba N.; Tweet, George; Tacke, Robert; Basat, Alp Bugra; Mikulski, Zbigniew; Togher, Susan; Miller, Jacqueline; Blatchley, Amy; Salek-Ardakani, Shahram; Darvas, Martin; Kaikkonen, Minna U.; Thomas, Graham; Lai-Wing-Sun, Sonia; Rezk, Ayman; Bar-Or, Amit; Glass, Christopher K.; Bandukwala, Hozefa; Hedrick, Catherine C.

    2016-01-01

    Molecular mechanisms linking the sympathetic stress response and inflammation remain enigmatic. Here we demonstrate that the transcription factor Nr4a1 regulates production of norepinephrine (NE) in macrophages, thereby limiting experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Lack of Nr4a1 in myeloid cells led to enhanced NE production, accelerated leukocyte infiltration to the central nervous system (CNS) and disease exacerbation in vivo. In contrast, myeloid-specific deletion of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, protected against EAE. Further, we found that Nr4a1 repressed autocrine NE production in macrophages by recruiting the corepressor CoREST to the Th promoter. Our data reveal a new role for macrophages in neuroinflammation and identify Nr4a1 as a key regulator of macrophage catecholamine production. PMID:26523867

  14. Altered cell cycle regulation helps stem-like carcinoma cells resist apoptosis

    OpenAIRE

    Dalton Stephen; Chappell James

    2010-01-01

    Abstract Reemergence of carcinomas following chemotherapy and/or radiotherapy is not well understood, but a recent study in BMC Cancer suggests that resistance to apoptosis resulting from altered cell cycle regulation is crucial. See research article: http://biomedcentral.com/1471-2407/10/166

  15. Regulation of DNA repair in serum-stimulated xeroderma pigmentosum cells

    OpenAIRE

    1984-01-01

    The regulation of DNA repair during serum stimulation of quiescent cells was examined in normal human cells, in fibroblasts from three xeroderma pigmentosum complementation groups (A, C, and D), in xeroderma pigmentosum variant cells, and in ataxia telangiectasia cells. The regulation of nucleotide excision repair was examined by exposing cells to ultraviolet irradiation at discrete intervals after cell stimulation. Similarly, base excision repair was quantitated after exposure to methylmetha...

  16. Expression Profile of microRNAs Regulating Proliferation and Differentiation in Mouse Adult Cardiac Stem Cells

    OpenAIRE

    Brás-Rosário, Luis; Matsuda, Alex; Pinheiro, Ana Isabel; Gardner, Rui; Lopes, Telma; Amaral, Andreia; Gama-Carvalho, Margarida

    2013-01-01

    The identification of cardiac cells with stem cell properties changed the paradigm of the heart as a post mitotic organ. These cells proliferate and differentiate into cardiomyocytes, endothelial and vascular smooth muscle cells, providing for cardiac cell homeostasis and regeneration. microRNAs are master switches controlling proliferation and differentiation, in particular regulating stem cell biology and cardiac development. Modulation of microRNAs -regulated gene expression networks holds...

  17. miRNAs regulate stem cell self-renewal and differentiation

    OpenAIRE

    Yu, Zuoren; Li, Yuan; Fan, Huimin; Liu, Zhongmin; Pestell, Richard G.

    2012-01-01

    Stem cells undergo symmetric and asymmetric divisions to generate differentiated cells and more stem cells. The balance between self-renewal and differentiation of stem cells is controlled by transcription factors, epigenetic regulatory networks, and microRNAs (miRNAs). Herein the miRNA involvement in the regulation of stem cell self-renewal and differentiation is summarized. miRNA contribution to malignancy through regulating cancer stem cells is described. In addition, the reciprocal associ...

  18. Self-Regulating Water-Separator System for Fuel Cells

    Science.gov (United States)

    Vasquez, Arturo; McCurdy, Kerri; Bradley, Karla F.

    2007-01-01

    proposed system would perform multiple coordinated functions in regulating the pressure of the oxidant gas (usually, pure oxygen) flowing to a fuelcell stack and in removing excess product water that is generated in the normal fuel-cell operation. The system could function in the presence or absence of gravitation, and in any orientation in a gravitational field. Unlike some prior systems for removing product water, the proposed system would not depend on hydrophobicity or hydrophilicity of surfaces that are subject to fouling and, consequently, to gradual deterioration in performance. Also unlike some prior systems, the proposed system would not include actively controlled electric motors for pumping; instead, motive power for separation and pumping away of product water would be derived primarily from the oxidant flow and perhaps secondarily from the fuel flow. The net effect of these and other features would be to make the proposed system more reliable and safer, relative to the prior systems. The proposed system (see figure) would include a pressure regulator and sensor in the oxidant supply just upstream from an ejector reactant pump. The pressure of the oxidant supply would depend on the consumption flow. In one of two control subsystems, the pressure of oxidant flowing from the supply to the ejector would be sensed and used to control the speed of a set of a reciprocating constant-displacement pump so that the volumetric flow of nominally incompressible water away from the system would slightly exceed the rate at which water was produced by the fuel cell(s). The two-phase (gas/liquid water) outlet stream from the fuel cell(s) would enter the water separator, a turbinelike centrifugal separator machine driven primarily by the oxidant gas stream. A second control subsystem would utilize feedback derived from the compressibility of the outlet stream: As the separator was emptied of liquid water, the compressibility of the pumped stream would increase. The

  19. WNT signaling regulates self-renewal and differentiation of prostate cancer cells with stem cell characteristics

    Institute of Scientific and Technical Information of China (English)

    Isabelle Bisson; David M Prowse

    2009-01-01

    Prostate cancer cells with stem cell characteristics were identified in human prostate cancer cell lines by their abil-ity to form from single cells self-renewing prostaspheres in non-adherent cultures. Prostaspheres exhibited heteroge-neous expression of proliferation, differentiation and stem cell-associated makers CD44, ABCG2 and CD133. Treat-ment with WNT inhibitors reduced both prostasphere size and self-renewal, In contrast, addition of Wnt3a caused increased prostasphere size and self-renewal, which was associated with a significant increase in nuclear β-catenin, keratin 18, CD133 and CD44 expression. As a high proportion of LNCaP and C4-2B cancer cells express androgen receptor we determined the effect of the androgen receptor antagonist bicalutamide. Androgen receptor inhibition reduced prostasphere size and expression of PSA, but did not inhibit prostasphere formation. These effects are con-sistent with the androgen-independent self-renewal of cells with stem cell characteristics and the androgen-dependent proliferation of transit amplifying cells. As the canonical WNT signaling effector β-catenin can also associate with the androgen receptor, we propose a model for tumour propagation involving a balance between WNT and androgen re-ceptor activity. That would affect the self-renewal of a cancer cell with stem cell characteristics and drive transit am-plifying cell proliferation and differentiation. In conclusion, we provide evidence that WNT activity regulates the self-renewal of prostate cancer cells with stem cell characteristics independently of androgen receptor activity. Inhibition of WNT signaling therefore has the potential to reduce the self-renewal of prostate cancer cells with stem cell charac-teristics and improve the therapeutic outcome.

  20. Peripheral monocytes are functionally altered and invade the CNS in ALS patients.

    Science.gov (United States)

    Zondler, Lisa; Müller, Kathrin; Khalaji, Samira; Bliederhäuser, Corinna; Ruf, Wolfgang P; Grozdanov, Veselin; Thiemann, Meinolf; Fundel-Clemes, Katrin; Freischmidt, Axel; Holzmann, Karlheinz; Strobel, Benjamin; Weydt, Patrick; Witting, Anke; Thal, Dietmar R; Helferich, Anika M; Hengerer, Bastian; Gottschalk, Kay-Eberhard; Hill, Oliver; Kluge, Michael; Ludolph, Albert C; Danzer, Karin M; Weishaupt, Jochen H

    2016-09-01

    Amyotrophic lateral sclerosis (ALS) is a devastating progressive neurodegenerative disease affecting primarily the upper and lower motor neurons. A common feature of all ALS cases is a well-characterized neuroinflammatory reaction within the central nervous system (CNS). However, much less is known about the role of the peripheral immune system and its interplay with CNS resident immune cells in motor neuron degeneration. Here, we characterized peripheral monocytes in both temporal and spatial dimensions of ALS pathogenesis. We found the circulating monocytes to be deregulated in ALS regarding subtype constitution, function and gene expression. Moreover, we show that CNS infiltration of peripheral monocytes correlates with improved motor neuron survival in a genetic ALS mouse model. Furthermore, application of human immunoglobulins or fusion proteins containing only the human Fc, but not the Fab antibody fragment, increased CNS invasion of peripheral monocytes and delayed the disease onset. Our results underline the importance of peripheral monocytes in ALS pathogenesis and are in agreement with a protective role of monocytes in the early phase of the disease. The possibility to boost this beneficial function of peripheral monocytes by application of human immunoglobulins should be evaluated in clinical trials. PMID:26910103

  1. Alternative splicing regulated by butyrate in bovine epithelial cells.

    Directory of Open Access Journals (Sweden)

    Sitao Wu

    Full Text Available As a signaling molecule and an inhibitor of histone deacetylases (HDACs, butyrate exerts its impact on a broad range of biological processes, such as apoptosis and cell proliferation, in addition to its critical role in energy metabolism in ruminants. This study examined the effect of butyrate on alternative splicing in bovine epithelial cells using RNA-seq technology. Junction reads account for 11.28 and 12.32% of total mapped reads between the butyrate-treated (BT and control (CT groups. 201,326 potential splicing junctions detected were supported by ≥ 3 junction reads. Approximately 94% of these junctions conformed to the consensus sequence (GT/AG while ~3% were GC/AG junctions. No AT/AC junctions were observed. A total of 2,834 exon skipping events, supported by a minimum of 3 junction reads, were detected. At least 7 genes, their mRNA expression significantly affected by butyrate, also had exon skipping events differentially regulated by butyrate. Furthermore, COL5A3, which was induced 310-fold by butyrate (FDR <0.001 at the gene level, had a significantly higher number of junction reads mapped to Exon#8 (Donor and Exon#11 (Acceptor in BT. This event had the potential to result in the formation of a COL5A3 mRNA isoform with 2 of the 69 exons missing. In addition, 216 differentially expressed transcript isoforms regulated by butyrate were detected. For example, Isoform 1 of ORC1 was strongly repressed by butyrate while Isoform 2 remained unchanged. Butyrate physically binds to and inhibits all zinc-dependent HDACs except HDAC6 and HDAC10. Our results provided evidence that butyrate also regulated deacetylase activities of classical HDACs via its transcriptional control. Moreover, thirteen gene fusion events differentially affected by butyrate were identified. Our results provided a snapshot into complex transcriptome dynamics regulated by butyrate, which will facilitate our understanding of the biological effects of butyrate and other HDAC

  2. Aebp2 as an epigenetic regulator for neural crest cells.

    Directory of Open Access Journals (Sweden)

    Hana Kim

    Full Text Available Aebp2 is a potential targeting protein for the mammalian Polycomb Repression Complex 2 (PRC2. We generated a mutant mouse line disrupting the transcription of Aebp2 to investigate its in vivo roles. Aebp2-mutant homozygotes were embryonic lethal while heterozygotes survived to adulthood with fertility. In developing mouse embryos, Aebp2 is expressed mainly within cells of neural crest origin. In addition, many heterozygotes display a set of phenotypes, enlarged colon and hypopigmentation, similar to those observed in human patients with Hirschsprung's disease and Waardenburg syndrome. These phenotypes are usually caused by the absence of the neural crest-derived ganglia in hindguts and melanocytes. ChIP analyses demonstrated that the majority of the genes involved in the migration and development process of neural crest cells are downstream target genes of AEBP2 and PRC2. Furthermore, expression analyses confirmed that some of these genes are indeed affected in the Aebp2 heterozygotes. Taken together, these results suggest that Aebp2 may regulate the migration and development of the neural crest cells through the PRC2-mediated epigenetic mechanism.

  3. Stretch-regulated Exocytosis/Endocytosis in Bladder Umbrella Cells

    Science.gov (United States)

    Truschel, Steven T.; Wang, Edward; Ruiz, Wily G.; Leung, Som-Ming; Rojas, Raul; Lavelle, John; Zeidel, Mark; Stoffer, David; Apodaca, Gerard

    2002-01-01

    The epithelium of the urinary bladder must maintain a highly impermeable barrier despite large variations in urine volume during bladder filling and voiding. To study how the epithelium accommodates these volume changes, we mounted bladder tissue in modified Ussing chambers and subjected the tissue to mechanical stretch. Stretching the tissue for 5 h resulted in a 50% increase in lumenal surface area (from ∼2900 to 4300 μm2), exocytosis of a population of discoidal vesicles located in the apical cytoplasm of the superficial umbrella cells, and release of secretory proteins. Surprisingly, stretch also induced endocytosis of apical membrane and 100% of biotin-labeled membrane was internalized within 5 min after stretch. The endocytosed membrane was delivered to lysosomes and degraded by a leupeptin-sensitive pathway. Last, we show that the exocytic events were mediated, in part, by a cyclic adenosine monophosphate, protein kinase A-dependent process. Our results indicate that stretch modulates mucosal surface area by coordinating both exocytosis and endocytosis at the apical membrane of umbrella cells and provide insight into the mechanism of how mechanical forces regulate membrane traffic in nonexcitable cells. PMID:11907265

  4. Genetic variants regulating immune cell levels in health and disease.

    Science.gov (United States)

    Orrù, Valeria; Steri, Maristella; Sole, Gabriella; Sidore, Carlo; Virdis, Francesca; Dei, Mariano; Lai, Sandra; Zoledziewska, Magdalena; Busonero, Fabio; Mulas, Antonella; Floris, Matteo; Mentzen, Wieslawa I; Urru, Silvana A M; Olla, Stefania; Marongiu, Michele; Piras, Maria G; Lobina, Monia; Maschio, Andrea; Pitzalis, Maristella; Urru, Maria F; Marcelli, Marco; Cusano, Roberto; Deidda, Francesca; Serra, Valentina; Oppo, Manuela; Pilu, Rosella; Reinier, Frederic; Berutti, Riccardo; Pireddu, Luca; Zara, Ilenia; Porcu, Eleonora; Kwong, Alan; Brennan, Christine; Tarrier, Brendan; Lyons, Robert; Kang, Hyun M; Uzzau, Sergio; Atzeni, Rossano; Valentini, Maria; Firinu, Davide; Leoni, Lidia; Rotta, Gianluca; Naitza, Silvia; Angius, Andrea; Congia, Mauro; Whalen, Michael B; Jones, Chris M; Schlessinger, David; Abecasis, Gonçalo R; Fiorillo, Edoardo; Sanna, Serena; Cucca, Francesco

    2013-09-26

    The complex network of specialized cells and molecules in the immune system has evolved to defend against pathogens, but inadvertent immune system attacks on "self" result in autoimmune disease. Both genetic regulation of immune cell levels and their relationships with autoimmunity are largely undetermined. Here, we report genetic contributions to quantitative levels of 95 cell types encompassing 272 immune traits, in a cohort of 1,629 individuals from four clustered Sardinian villages. We first estimated trait heritability, showing that it can be substantial, accounting for up to 87% of the variance (mean 41%). Next, by assessing ∼8.2 million variants that we identified and confirmed in an extended set of 2,870 individuals, 23 independent variants at 13 loci associated with at least one trait. Notably, variants at three loci (HLA, IL2RA, and SH2B3/ATXN2) overlap with known autoimmune disease associations. These results connect specific cellular phenotypes to specific genetic variants, helping to explicate their involvement in disease. PMID:24074872

  5. Neural stem cells and the regulation of adult neurogenesis

    Directory of Open Access Journals (Sweden)

    Conover Joanne C

    2003-11-01

    Full Text Available Abstract Presumably, the 'hard-wired' neuronal circuitry of the adult brain dissuades addition of new neurons, which could potentially disrupt existing circuits. This is borne out by the fact that, in general, new neurons are not produced in the mature brain. However, recent studies have established that the adult brain does maintain discrete regions of neurogenesis from which new neurons migrate and become incorporated into the functional circuitry of the brain. These neurogenic zones appear to be vestiges of the original developmental program that initiates brain formation. The largest of these germinal regions in the adult brain is the subventricular zone (SVZ, which lines the lateral walls of the lateral ventricles. Neural stem cells produce neuroblasts that migrate from the SVZ along a discrete pathway, the rostral migratory stream, into the olfactory bulb where they form mature neurons involved in the sense of smell. The subgranular layer (SGL of the hippocampal dentate gyrus is another neurogenic region; new SGL neurons migrate only a short distance and differentiate into hippocampal granule cells. Here, we discuss the surprising finding of neural stem cells in the adult brain and the molecular mechanisms that regulate adult neurogenesis.

  6. Cytokinin signaling regulates pavement cell morphogenesis in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Hongjiang Li; Tongda Xu; Deshu Lin; Mingzhang Wen; Mingtang Xie; Jér(o)me Duclercq; Agnieszka Bielach

    2013-01-01

    The puzzle piece-shaped Arabidopsis leaf pavement cells (PCs) with interdigitated lobes and indents is a good model system to investigate the mechanisms that coordinate cell polarity and shape formation within a tissue.Auxin has been shown to coordinate the interdigitation by activating ROP GTPase-dependent signaling pathways.To identify additional components or mechanisms,we screened for mutants with abnormal PC morphogenesis and found that cytokinin signaling regulates the PC interdigitation pattern.Reduction in cytokinin accumulation and defects in cytokinin signaling (such as in ARR7-over-expressing lines,the ahk3cre1 cytokinin receptor mutant,and the ahp12345 cytokinin signaling mutant) enhanced PC interdigitation,whereas over-production of cytokinin and over-activation of cytokinin signaling in an ARR20 over-expression line delayed or abolished PC interdigitation throughout the cotyledon.Genetic and biochemical analyses suggest that cytokinin signaling acts upstream of ROPs to suppress the formation of interdigitated pattern.Our results provide novel mechanistic understanding of the pathways controlling PC shape and uncover a new role for cytokinin signaling in cell morphogenesis.

  7. Dendritic Cells and Multiple Sclerosis: Disease, Tolerance and Therapy

    Directory of Open Access Journals (Sweden)

    Mohammad G. Mohammad

    2012-12-01

    Full Text Available Multiple sclerosis (MS is a devastating neurological disease that predominantly affects young adults resulting in severe personal and economic impact. The majority of therapies for this disease were developed in, or are beneficial in experimental autoimmune encephalomyelitis (EAE, the animal model of MS. While known to target adaptive anti-CNS immune responses, they also target, the innate immune arm. This mini-review focuses on the role of dendritic cells (DCs, the professional antigen presenting cells of the innate immune system. The evidence for a role for DCs in the appropriate regulation of anti-CNS autoimmune responses and their role in MS disease susceptibility and possible therapeutic utility are discussed. Additionally, the current controversy regarding the evidence for the presence of functional DCs in the normal CNS is reviewed. Furthermore, the role of CNS DCs and potential routes of their intercourse between the CNS and cervical lymph nodes are considered. Finally, the future role that this nexus between the CNS and the cervical lymph nodes might play in site directed molecular and cellular therapy for MS is outlined.

  8. The associated regulators and signal pathway in rILl-16/CD4 mediated growth regulation in Jurkat cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    IL-16 is a ligand and chemotactic factor for CD4+ T cells. IL-16 inhibits the CD3 mediated lymphocyteactivation and proliferation. The effects of IL-16 on the target cells are dependent on the cell type, thepresence of co-activators etc. To understand the regulation function and mechanism of IL-16 on targetcells, we used a 130 a.a. recombinant IL-16 to study its effects on the growth of Jurkat T leukemia cellsin vitro. We found that the rIL-16 stimulated the proliferation of Jurkat cells at low dose (10-9M), butinhibited the growth of the cells at higher concentration (10-5M). Results showed that 10-5 M of rIL-16treatment induced an enhanced apoptosis in Jurkat cells. The treatment blocked the expression of FasL, butup-regulated the c-myc and Bid expression in the cells. Pre-treatment of PKC inhibitor or MEK1 inhibitormarkedly increased or decreased the rIL-16 induced growth-inhibiting effects on Jurkat cells, respectively.The results suggested that the rIL-16 might be a regulator for the growth or apoptosis of Jurkat cells ata dose-dependent manner. The growth-inhibiting effects of rIL-16 might be Fas/FasL independent, but,associated with the activation of PKC, up-regulated expression of c-Myc and Bid, and the participation ofthe ERK signal pathway in Jurkat cells.

  9. Nitric Oxide Prevents Mouse Embryonic Stem Cell Differentiation Through Regulation of Gene Expression, Cell Signaling, and Control of Cell Proliferation.

    Science.gov (United States)

    Tapia-Limonchi, Rafael; Cahuana, Gladys M; Caballano-Infantes, Estefania; Salguero-Aranda, Carmen; Beltran-Povea, Amparo; Hitos, Ana B; Hmadcha, Abdelkrim; Martin, Franz; Soria, Bernat; Bedoya, Francisco J; Tejedo, Juan R

    2016-09-01

    Nitric oxide (NO) delays mouse embryonic stem cell (mESC) differentiation by regulating genes linked to pluripotency and differentiation. Nevertheless, no profound study has been conducted on cell differentiation regulation by this molecule through signaling on essential biological functions. We sought to demonstrate that NO positively regulates the pluripotency transcriptional core, enforcing changes in the chromatin structure, in addition to regulating cell proliferation, and signaling pathways with key roles in stemness. Culturing mESCs with 2 μM of the NO donor diethylenetriamine/NO (DETA/NO) in the absence of leukemia inhibitory factor (LIF) induced significant changes in the expression of 16 genes of the pluripotency transcriptional core. Furthermore, treatment with DETA/NO resulted in a high occupancy of activating H3K4me3 at the Oct4 and Nanog promoters and repressive H3K9me3 and H3k27me3 at the Brachyury promoter. Additionally, the activation of signaling pathways involved in pluripotency, such as Gsk3-β/β-catenin, was observed, in addition to activation of PI3 K/Akt, which is consistent with the protection of mESCs from cell death. Finally, a decrease in cell proliferation coincides with cell cycle arrest in G2/M. Our results provide novel insights into NO-mediated gene regulation and cell proliferation and suggest that NO is necessary but not sufficient for the maintenance of pluripotency and the prevention of cell differentiation. J. Cell. Biochem. 117: 2078-2088, 2016. © 2016 Wiley Periodicals, Inc. PMID:26853909

  10. Possible Involvement of TLRs and Hemichannels in Stress-Induced CNS Dysfunction via Mastocytes, and Glia Activation

    OpenAIRE

    Adam Aguirre; Maturana, Carola J.; Paloma A. Harcha; Sáez, Juan C.

    2013-01-01

    In the central nervous system (CNS), mastocytes and glial cells (microglia, astrocytes and oligodendrocytes) function as sensors of neuroinflammatory conditions, responding to stress triggers or becoming sensitized to subsequent proinflammatory challenges. The corticotropin-releasing hormone and glucocorticoids are critical players in stress-induced mastocyte degranulation and potentiation of glial inflammatory responses, respectively. Mastocytes and glial cells express different toll-like re...

  11. A philosophy for CNS radiotracer design.

    Science.gov (United States)

    Van de Bittner, Genevieve C; Ricq, Emily L; Hooker, Jacob M

    2014-10-21

    Decades after its discovery, positron emission tomography (PET) remains the premier tool for imaging neurochemistry in living humans. Technological improvements in radiolabeling methods, camera design, and image analysis have kept PET in the forefront. In addition, the use of PET imaging has expanded because researchers have developed new radiotracers that visualize receptors, transporters, enzymes, and other molecular targets within the human brain. However, of the thousands of proteins in the central nervous system (CNS), researchers have successfully imaged fewer than 40 human proteins. To address the critical need for new radiotracers, this Account expounds on the decisions, strategies, and pitfalls of CNS radiotracer development based on our current experience in this area. We discuss the five key components of radiotracer development for human imaging: choosing a biomedical question, selection of a biological target, design of the radiotracer chemical structure, evaluation of candidate radiotracers, and analysis of preclinical imaging. It is particularly important to analyze the market of scientists or companies who might use a new radiotracer and carefully select a relevant biomedical question(s) for that audience. In the selection of a specific biological target, we emphasize how target localization and identity can constrain this process and discuss the optimal target density and affinity ratios needed for binding-based radiotracers. In addition, we discuss various PET test-retest variability requirements for monitoring changes in density, occupancy, or functionality for new radiotracers. In the synthesis of new radiotracer structures, high-throughput, modular syntheses have proved valuable, and these processes provide compounds with sites for late-stage radioisotope installation. As a result, researchers can manage the time constraints associated with the limited half-lives of isotopes. In order to evaluate brain uptake, a number of methods are available

  12. GATA-1 directly regulates Nanog in mouse embryonic stem cells

    International Nuclear Information System (INIS)

    Nanog safeguards pluripotency in mouse embryonic stem cells (mESCs). Insight into the regulation of Nanog is important for a better understanding of the molecular mechanisms that control pluripotency of mESCs. In a silico analysis, we identify four GATA-1 putative binding sites in Nanog proximal promoter. The Nanog promoter activity can be significantly repressed by ectopic expression of GATA-1 evidenced by a promoter reporter assay. Mutation studies reveal that one of the four putative binding sites counts for GATA-1 repressing Nanog promoter activity. Direct binding of GATA-1 on Nanog proximal promoter is confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation. Our data provide new insights into the expanded regulatory circuitry that coordinates Nanog expression. - Highlights: • The Nanog proximal promoter conceives functional element for GATA-1. • GATA-1 occupies the Nanog proximal promoter in vitro and in vivo. • GATA-1 transcriptionally suppresses Nanog

  13. Cloning and analysis of genes regulating plant cell growth

    International Nuclear Information System (INIS)

    The aims of this work are to identify, clone and analyze genes involved in the regulation of plant cell growth. To do this, we have induced tumors on Arabidopsis thaliana by exposing seed or germinating seedlings to ionizing radiation. The tumors which developed on the plants derived from these seed were excised and established in culture. Unlike normal tissue explants, the tumors are able to grow on hormone-free medium suggesting changes in growth control (either hormonal or other) induced by the radiation exposure. This progress report describes work aimed at characterizing these tumors at the physiological and cellular levels and at determining the molecular basis of the changes leading to the tumorous phenotype

  14. GATA-1 directly regulates Nanog in mouse embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wen-Zhong; Ai, Zhi-Ying [College of Life Sciences, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China); Wang, Zhi-Wei [School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027 (China); Chen, Lin-Lin [College of Life Sciences, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China); Guo, Ze-Kun, E-mail: gzknwaf@126.com [College of Veterinary Medicine, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China); Zhang, Yong, E-mail: zylabnwaf@126.com [College of Veterinary Medicine, Northwest A& F University, Yangling 712100 (China); Key Laboratory of Animal Biotechnology, Ministry of Agriculture, Northwest A& F University, Yangling 712100 (China)

    2015-09-25

    Nanog safeguards pluripotency in mouse embryonic stem cells (mESCs). Insight into the regulation of Nanog is important for a better understanding of the molecular mechanisms that control pluripotency of mESCs. In a silico analysis, we identify four GATA-1 putative binding sites in Nanog proximal promoter. The Nanog promoter activity can be significantly repressed by ectopic expression of GATA-1 evidenced by a promoter reporter assay. Mutation studies reveal that one of the four putative binding sites counts for GATA-1 repressing Nanog promoter activity. Direct binding of GATA-1 on Nanog proximal promoter is confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation. Our data provide new insights into the expanded regulatory circuitry that coordinates Nanog expression. - Highlights: • The Nanog proximal promoter conceives functional element for GATA-1. • GATA-1 occupies the Nanog proximal promoter in vitro and in vivo. • GATA-1 transcriptionally suppresses Nanog.

  15. Substrate stiffness regulates extracellular matrix deposition by alveolar epithelial cells

    Directory of Open Access Journals (Sweden)

    Jessica L Eisenberg

    2011-01-01

    Full Text Available Jessica L Eisenberg1,2, Asmahan Safi3, Xiaoding Wei3, Horacio D Espinosa3, GR Scott Budinger2, Desire Takawira1, Susan B Hopkinson1, Jonathan CR Jones1,21Department of Cell and Molecular Biology, 2Division of Pulmonary Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; 3Department of Mechanical Engineering, Northwestern University, Evanston, IL, USAAim: The aim of the study was to address whether a stiff substrate, a model for pulmonary fibrosis, is responsible for inducing changes in the phenotype of alveolar epithelial cells (AEC in the lung, including their deposition and organization of extracellular matrix (ECM proteins.Methods: Freshly isolated lung AEC from male Sprague Dawley rats were seeded onto polyacrylamide gel substrates of varying stiffness and analyzed for expression and organization of adhesion, cytoskeletal, differentiation, and ECM components by Western immunoblotting and confocal immunofluorescence microscopy.Results: We observed that substrate stiffness influences cell morphology and the organization of focal adhesions and the actin cytoskeleton. Surprisingly, however, we found that substrate stiffness has no influence on the differentiation of type II into type I AEC, nor does increased substrate stiffness lead to an epithelial–mesenchymal transition. In contrast, our data indicate that substrate stiffness regulates the expression of the α3 laminin subunit by AEC and the organization of both fibronectin and laminin in their ECM.Conclusions: An increase in substrate stiffness leads to enhanced laminin and fibronectin assembly into fibrils, which likely contributes to the disease phenotype in the fibrotic lung.Keywords: alveolar epithelial cells, fibrosis, extracellular matrix, substrate stiffness

  16. Prion protein expression regulates embryonic stem cell pluripotency and differentiation.

    Directory of Open Access Journals (Sweden)

    Alberto Miranda

    Full Text Available Cellular prion protein (PRNP is a glycoprotein involved in the pathogenesis of transmissible spongiform encephalopathies (TSEs. Although the physiological function of PRNP is largely unknown, its key role in prion infection has been extensively documented. This study examines the functionality of PRNP during the course of embryoid body (EB differentiation in mouse Prnp-null (KO and WT embryonic stem cell (ESC lines. The first feature observed was a new population of EBs that only appeared in the KO line after 5 days of differentiation. These EBs were characterized by their expression of several primordial germ cell (PGC markers until Day 13. In a comparative mRNA expression analysis of genes playing an important developmental role during ESC differentiation to EBs, Prnp was found to participate in the transcription of a key pluripotency marker such as Nanog. A clear switching off of this gene on Day 5 was observed in the KO line as opposed to the WT line, in which maximum Prnp and Nanog mRNA levels appeared at this time. Using a specific antibody against PRNP to block PRNP pathways, reduced Nanog expression was confirmed in the WT line. In addition, antibody-mediated inhibition of ITGB5 (integrin αvβ5 in the KO line rescued the low expression of Nanog on Day 5, suggesting the regulation of Nanog transcription by Prnp via this Itgb5. mRNA expression analysis of the PRNP-related proteins PRND (Doppel and SPRN (Shadoo, whose PRNP function is known to be redundant, revealed their incapacity to compensate for the absence of PRNP during early ESC differentiation. Our findings provide strong evidence for a relationship between Prnp and several key pluripotency genes and attribute Prnp a crucial role in regulating self-renewal/differentiation status of ESC, confirming the participation of PRNP during early embryogenesis.

  17. Trichostatin A Regulates hGCN5 Expression and Cell Cycle on Daudi Cells in vitro

    Institute of Scientific and Technical Information of China (English)

    LIU Hongli; CHEN Yan; CUI Guohui; WU Gang; WANG Tao; HU Jianli

    2006-01-01

    The expression of human general control of amino acid synthesis protein 5 (hGCN5) in human Burkitt's lymphoma Daudi cells in vitro, effects of Trichostatin A (TSA) on cell proliferation and apoptosis and the molecular mechanism of TSA inhibiting proliferation of Daudi cells were investigated. The effects of TSA on the growth of Daudi cells were studied by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. The effect of TSA on the cell cycle of Daudi cells was assayed by a propidium iodide method. Immunochemistry and Western blot were used to detect the expression of hGCN5. The proliferation of Daudi cells was decreased in TSA-treated group with a 24 h IC50 value of 415.3979 μg/L. TSA induced apoptosis of Daudi cells in a time- and dose-dependent manner. Treatment with TSA (200 and 400 μg/L) for 24 h, the apoptosis rates of Daudi cells were (14.74±2.04) % and (17.63±1.25) %, respectively. The cell cycle was arrested in G0/G1 phase (50, 100 μtg/L) and in G2/M phase (200 μg/L) by treatment with TSA for 24 h.The expression of hGCN5 protein in Daudi cells was increased in 24 h TSA-treated group by immunochemistry and Western blot (P<0.05). It was suggested that TSA as HDACIs could increase the expression of hGCN5 in Daudi cells, and might play an important role in regulating the proliferation and apoptosis of B-NHL cell line Daudi cells.

  18. Regulation of Taurine transporter activity in cultured rat retinal ganglion cells and rat retinal Muller Cells

    International Nuclear Information System (INIS)

    Diabetic retinopathy is one of the most common complications of diabetes. The amino acid taurine is believed to play an antioxidant protective role in diabetic retinopathy through the scavenging of the reactive species. It is not well established whether taurine uptake is altered in retina cells during diabetic conditions. Thus, the present study was designed to investigate the changes in taurine transport in cultures of rat retinal Muller cells and rat retinal ganglion cells under conditions associated with diabetes. Taurine was abundantly taken up by retinal Muller cells and rat retinal ganglion cells under normal glycemic condition. Taurine was actively transported to rat Muller cells and rat retinal ganglion cells in a Na and Cl dependant manner. Taurine uptake further significantly elevated in both type of cells after the incubation with high glucose concentration. This effect could be attributed to the increase in osmolarity. Because Nitric Oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we also determined the activity of taurine transporter in cultured rat retinal Muller cells and rat retinal ganglion cells in the presence of the NO donors, SIN-1 and SNAP. Taurine uptake was elevated above control value after 24-h incubation with low concentration of NO donors. We finally investigated the ability of neurotoxic glutamate to change taurine transporter activity in both types of cells. Uptake of taurine was significantly increased in rat retinal ganglion cells when only incubated with high concentration of glutamate. Our data provide evidence that taurine transporter is present in cultured rat retinal ganglion and Muller cells and is regulated by hyperosmolarity. The data are relevant to disease such as diabetes and neuronal degeneration where retinal cell volume may dramatically change. (author)

  19. A family business: stem cell progeny join the niche to regulate homeostasis.

    Science.gov (United States)

    Hsu, Ya-Chieh; Fuchs, Elaine

    2012-02-01

    Stem cell niches, the discrete microenvironments in which the stem cells reside, play a dominant part in regulating stem cell activity and behaviours. Recent studies suggest that committed stem cell progeny become indispensable components of the niche in a wide range of stem cell systems. These unexpected niche inhabitants provide versatile feedback signals to their stem cell parents. Together with other heterologous cell types that constitute the niche, they contribute to the dynamics of the microenvironment. As progeny are often located in close proximity to stem cell niches, similar feedback regulations may be the underlying principles shared by different stem cell systems. PMID:22266760

  20. Tetrahydrouridine inhibits cell proliferation through cell cycle regulation regardless of cytidine deaminase expression levels.

    Directory of Open Access Journals (Sweden)

    Naotake Funamizu

    Full Text Available Tetrahydrouridine (THU is a well characterized and potent inhibitor of cytidine deaminase (CDA. Highly expressed CDA catalyzes and inactivates cytidine analogues, ultimately contributing to increased gemcitabine resistance. Therefore, a combination therapy of THU and gemcitabine is considered to be a potential and promising treatment for tumors with highly expressed CDA. In this study, we found that THU has an alternative mechanism for inhibiting cell growth which is independent of CDA expression. Three different carcinoma cell lines (MIAPaCa-2, H441, and H1299 exhibited decreased cell proliferation after sole administration of THU, while being unaffected by knocking down CDA. To investigate the mechanism of THU-induced cell growth inhibition, cell cycle analysis using flow cytometry was performed. This analysis revealed that THU caused an increased rate of G1-phase occurrence while S-phase occurrence was diminished. Similarly, Ki-67 staining further supported that THU reduces cell proliferation. We also found that THU regulates cell cycle progression at the G1/S checkpoint by suppressing E2F1. As a result, a combination regimen of THU and gemcitabine might be a more effective therapy than previously believed for pancreatic carcinoma since THU works as a CDA inhibitor, as well as an inhibitor of cell growth in some types of pancreatic carcinoma cells.